Durability of Original Monovalent mRNA Vaccine Effectiveness Against COVID-19 Omicron-Associated Hospitalization in Children and Adolescents - United States, 2021-2023.

Autor: Zambrano LD, Newhams MM, Simeone RM, Payne AB, Wu M, Orzel-Lockwood AO, Halasa NB, Calixte JM, Pannaraj PS, Mongkolrattanothai K, Boom JA, Sahni LC, Kamidani S, Chiotos K, Cameron MA, Maddux AB, Irby K, Schuster JE, Mack EH, Biggs A, Coates BM, Michelson KN, Bline KE, Nofziger RA, Crandall H, Hobbs CV, Gertz SJ, Heidemann SM, Bradford TT, Walker TC, Schwartz SP, Staat MA, Bhumbra SS, Hume JR, Kong M, Stockwell MS, Connors TJ, Cullimore ML, Flori HR, Levy ER, Cvijanovich NZ, Zinter MS, Maamari M, Bowens C, Zerr DM, Guzman-Cottrill JA, Gonzalez I, Campbell AP, Randolph AG

Publikováno v: MMWR. Morbidity and mortality weekly report [MMWR Morb Mortal Wkly Rep] 2024 Apr 18; Vol. 73 (15), pp. 330-338. Date of Electronic Publication: 2024 Apr 18.

Myeloid-derived suppressor cells and T cell populations in children with Multisystem Inflammatory Syndrome.

Autor: Bline KE; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA. Katherine.Bline@nationwidechildrens.org.; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA. Katherine.Bline@nationwidechildrens.org., Wilt AL; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA., Alexander RN; Biostatistics Resource at Nationwide Children's Hospital, Columbus, OH, USA., Andrews AN; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA., Mertz SE; Center for Vaccines and Immunity, Nationwide Children's Hospital, Columbus, OH, USA., Ye F; Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA., Steele LM; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA., Wolfe AL; Division of Critical Care Medicine, Nationwide Children's Hospital, Columbus, OH, USA., Mejias A; Department of Infectious Disease, St. Jude Children's Research Hospital, Memphis, TN, USA., Ramilo O; Department of Infectious Disease, St. Jude Children's Research Hospital, Memphis, TN, USA.

Publikováno v: Pediatric research [Pediatr Res] 2024 Apr; Vol. 95 (5), pp. 1288-1294. Date of Electronic Publication: 2023 Dec 02.

Effectiveness of Maternal mRNA COVID-19 Vaccination During Pregnancy Against COVID-19-Associated Hospitalizations in Infants Aged <6 Months During SARS-CoV-2 Omicron Predominance - 20 States, March 9, 2022-May 31, 2023.

Autor: Simeone RM, Zambrano LD, Halasa NB, Fleming-Dutra KE, Newhams MM, Wu MJ, Orzel-Lockwood AO, Kamidani S, Pannaraj PS, Irby K, Maddux AB, Hobbs CV, Cameron MA, Boom JA, Sahni LC, Kong M, Nofziger RA, Schuster JE, Crandall H, Hume JR, Staat MA, Mack EH, Bradford TT, Heidemann SM, Levy ER, Gertz SJ, Bhumbra SS, Walker TC, Bline KE, Michelson KN, Zinter MS, Flori HR, Campbell AP, Randolph AG

Publikováno v: MMWR. Morbidity and mortality weekly report [MMWR Morb Mortal Wkly Rep] 2023 Sep 29; Vol. 72 (39), pp. 1057-1064. Date of Electronic Publication: 2023 Sep 29.

BNT162b2 mRNA Vaccination Against Coronavirus Disease 2019 is Associated With a Decreased Likelihood of Multisystem Inflammatory Syndrome in Children Aged 5-18 Years-United States, July 2021 - April 2022.

Autor: Zambrano LD; CDC COVID-19 Response Team, Atlanta, Georgia, USA., Newhams MM; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA., Olson SM; CDC COVID-19 Response Team, Atlanta, Georgia, USA., Halasa NB; Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA., Price AM; CDC COVID-19 Response Team, Atlanta, Georgia, USA., Orzel AO; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA., Young CC; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA., Boom JA; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas, USA., Sahni LC; Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston, Texas, USA., Maddux AB; Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado, USA., Bline KE; Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA., Kamidani S; The Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA., Tarquinio KM; Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, Georgia, USA., Chiotos K; Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA., Schuster JE; Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri, USA., Cullimore ML; Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, Nebraska, USA., Heidemann SM; Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit, Michigan, USA., Hobbs CV; Division of Infectious Diseases, Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi, USA., Nofziger RA; Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron, Ohio, USA., Pannaraj PS; Division of Infectious Diseases, Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California, USA., Cameron MA; Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego, California, USA., Walker TC; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina, USA., Schwartz SP; Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill, North Carolina, USA., Michelson KN; Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA., Coates BM; Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA., Flori HR; Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor, Michigan, USA., Mack EH; Division of Pediatric Critical Care Medicine, Medical University of South Carolina, Charleston, South Carolina, USA., Smallcomb L; Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA., Gertz SJ; Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, New Jersey, USA., Bhumbra SS; The Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA., Bradford TT; Division of Cardiology, Department of Pediatrics, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans, Louisiana, USA., Levy ER; Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, Minnesota, USA., Kong M; Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA., Irby K; Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock, Arkansas, USA., Cvijanovich NZ; Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland, California, USA., Zinter MS; Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, Department of Pediatrics, University of California, San Francisco, San Francisco, California, USA., Bowens C; Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas, Texas, USA., Crandall H; Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA., Hume JR; Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, USA., Patel MM; CDC COVID-19 Response Team, Atlanta, Georgia, USA., Campbell AP; CDC COVID-19 Response Team, Atlanta, Georgia, USA., Randolph AG; Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.; Departments of Anesthesia and Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.

Publikováno v: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America [Clin Infect Dis] 2023 Feb 08; Vol. 76 (3), pp. e90-e100.

Maternal Vaccination and Risk of Hospitalization for Covid-19 among Infants.

Autor: Halasa NB; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Olson SM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Staat MA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Newhams MM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Price AM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Pannaraj PS; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Boom JA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Sahni LC; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Chiotos K; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Cameron MA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Bline KE; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Hobbs CV; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Maddux AB; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Coates BM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Michelson KN; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Heidemann SM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Irby K; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Nofziger RA; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Mack EH; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Smallcomb L; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Schwartz SP; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Walker TC; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Gertz SJ; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Schuster JE; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Kamidani S; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Tarquinio KM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Bhumbra SS; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Maamari M; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Hume JR; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Crandall H; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Levy ER; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Zinter MS; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Bradford TT; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Flori HR; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Cullimore ML; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Kong M; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Cvijanovich NZ; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Gilboa SM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Polen KN; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Campbell AP; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Randolph AG; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.)., Patel MM; From the Division of Pediatric Infectious Diseases, Department of Pediatrics, Vanderbilt University Medical Center, Nashville (N.B.H.); the Covid-19 Response Team, Centers for Disease Control and Prevention (S.M.O., A.M.P., S.M.G., K.N.P., A.P.C., M.M.P.), the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics, Emory University School of Medicine (S.K.), and the Division of Critical Care Medicine, Department of Pediatrics, Emory University School of Medicine, Children's Healthcare of Atlanta (K.M.T.) - all in Atlanta; the Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati (M.A.S.), the Division of Pediatric Critical Care Medicine, Nationwide Children's Hospital, Columbus (K.E.B.), and the Division of Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron (R.A.N.) - all in Ohio; the Department of Anesthesiology, Critical Care, and Pain Medicine, Boston Children's Hospital (M.M.N., A.G.R.), and the Departments of Anaesthesia and Pediatrics, Harvard Medical School (A.G.R.) - both in Boston; the Division of Infectious Diseases, Children's Hospital Los Angeles, and the Departments of Pediatrics and Molecular Microbiology and Immunology, University of Southern California, Los Angeles, Los Angeles (P.S.P.), the Division of Pediatric Hospital Medicine, UC San Diego-Rady Children's Hospital, San Diego (M.A.C.), the Department of Pediatrics, Divisions of Critical Care Medicine and Allergy, Immunology, and Bone Marrow Transplant, University of California, San Francisco, San Francisco (M.S.Z.), and the Division of Critical Care Medicine, UCSF Benioff Children's Hospital, Oakland (N.Z.C.) - all in California; the Department of Pediatrics, Baylor College of Medicine, Immunization Project, Texas Children's Hospital, Houston (J.A.B., L.C.S.); the Division of Critical Care Medicine, Department of Anesthesiology and Critical Care, Children's Hospital of Philadelphia, Philadelphia (K.C.); the Department of Pediatrics, Division of Infectious Diseases, University of Mississippi Medical Center, Jackson (C.V.H.); the Department of Pediatrics, Section of Critical Care Medicine, University of Colorado School of Medicine, and Children's Hospital Colorado, Aurora (A.B.M.); the Division of Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago (B.M.C., K.N.M.); the Division of Pediatric Critical Care Medicine, Children's Hospital of Michigan, Central Michigan University, Detroit (S.M.H.), and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, Mott Children's Hospital and University of Michigan, Ann Arbor (H.R.F.); the Section of Pediatric Critical Care, Department of Pediatrics, Arkansas Children's Hospital, Little Rock (K.I.); the Division of Pediatric Critical Care Medicine (E.H.M.), and the Department of Pediatrics (L.S.), Medical University of South Carolina, Charleston; the Department of Pediatrics, University of North Carolina at Chapel Hill Children's Hospital, Chapel Hill (S.P.S., T.C.W.); the Division of Pediatric Critical Care, Department of Pediatrics, Cooperman Barnabas Medical Center, Livingston, NJ (S.J.G.); the Division of Pediatric Infectious Diseases, Department of Pediatrics, Children's Mercy Kansas City, Kansas City, Missouri (J.E.S.); the Ryan White Center for Pediatric Infectious Disease and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis (S.S.B.); the Department of Pediatrics, Division of Critical Care Medicine, University of Texas Southwestern, Children's Medical Center, Dallas (M.M.); the Division of Pediatric Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis (J.R.H.), and the Divisions of Pediatric Infectious Diseases and Pediatric Critical Care Medicine, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester (E.R.L.) - both in Minnesota; the Division of Pediatric Critical Care, Department of Pediatrics, University of Utah, Salt Lake City (H.C.); the Department of Pediatrics, Division of Cardiology, Louisiana State University Health Sciences Center and Children's Hospital of New Orleans, New Orleans (T.T.B.); the Division of Pediatric Critical Care, Department of Pediatrics, Children's Hospital and Medical Center, Omaha, NE (M.L.C.); and the Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Alabama at Birmingham, Birmingham (M.K.).

Publikováno v: The New England journal of medicine [N Engl J Med] 2022 Jul 14; Vol. 387 (2), pp. 109-119. Date of Electronic Publication: 2022 Jun 22.