Effectiveness of CoronaVac among healthcare workers in the setting of high SARS-CoV-2 Gamma variant transmission in Manaus, Brazil: A test-negative case-control study.

Autor:	Hitchings MDT; Department of Biology, University of Florida, Gainesville, FL, USA.; Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA., Ranzani OT; Pulmonary Division, Heart Institute (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, São Paulo, SP, Brazil.; Barcelona Institute for Global Health, ISGlobal, Barcelona, Spain., Torres MSS; Municipal Health Secretary of Manaus, Brazil, AM, Brazil., de Oliveira SB; Pan American Health Organization, Brasília, DF, Brazil.; Universidade de Brasília, Brasília, DF, Brazil., Almiron M; Pan American Health Organization, Brasília, DF, Brazil., Said R; Pan American Health Organization, Brasília, DF, Brazil., Borg R; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA., Schulz WL; Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, CT, USA.; Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT, USA., de Oliveira RD; State University of Mato Grosso do Sul - UEMS, Dourados, MS, Brazil., da Silva PV; Universidade Federal de Mato Grosso do Sul - UFMS, Campo Grande, MS, Brazil., de Castro DB; Fundação de Vigilância em Saúde do Estado do Amazonas, Manaus, AM, Brazil., Sampaio VS; Fundação de Vigilância em Saúde do Estado do Amazonas, Manaus, AM, Brazil., de Albuquerque BC; Fundação de Vigilância em Saúde do Estado do Amazonas, Manaus, AM, Brazil., Ramos TCA; Fundação de Vigilância em Saúde do Estado do Amazonas, Manaus, AM, Brazil., Fraxe SHH; Municipal Health Secretary of Manaus, Brazil, AM, Brazil., da Costa CF; Fundação de Vigilância em Saúde do Estado do Amazonas, Manaus, AM, Brazil., Naveca FG; Fiocruz, Instituto Leônidas e Maria Deane, Manaus, AM, Brazil., Siqueira AM; Instituto Nacional de Infectologia Carlos Chagas-Fiocruz, Rio de Janeiro, RJ, Brazil., de Araújo WN; Pan American Health Organization, Brasília, DF, Brazil.; Universidade de Brasília, Brasília, DF, Brazil.; National Institute for Science and Technology for Health Technology Assessment, Porto Alegre, RS, Brazil., Andrews JR; Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA., Cummings DAT; Department of Biology, University of Florida, Gainesville, FL, USA.; Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA., Ko AI; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.; Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, BA, Brazil., Croda J; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.; Universidade Federal de Mato Grosso do Sul - UFMS, Campo Grande, MS, Brazil.; Fiocruz Mato Grosso do Sul, Fundação Oswaldo Cruz, Campo Grande, MS, Brazil.
Jazyk:	angličtina
Zdroj:	Lancet regional health. Americas [Lancet Reg Health Am] 2021 Sep; Vol. 1, pp. 100025. Date of Electronic Publication: 2021 Jul 25.
DOI:	10.1016/j.lana.2021.100025
Abstrakt:	Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, Gamma, emerged in the city of Manaus in late 2020 during a large resurgence of coronavirus disease (COVID-19), and has spread throughout Brazil. The effectiveness of vaccines in settings with widespread Gamma variant transmission has not been reported. Methods: We performed a matched test-negative case-control study to estimate the effectiveness of an inactivated vaccine, CoronaVac, in healthcare workers (HCWs) in Manaus, where the Gamma variant accounted for 86% of genotyped SARS-CoV-2 samples at the peak of its epidemic. We performed an early analysis of effectiveness following administration of at least one vaccine dose and an analysis of effectiveness of the two-dose schedule. The primary outcome was symptomatic SARS-CoV-2 infection. Findings: For the early at-least-one-dose and two-dose analyses the study population was, respectively, 53,176 and 53,153 HCWs residing in Manaus and aged 18 years or older, with complete information on age, residence, and vaccination status. Among 53,153 HCWs eligible for the two-dose analysis, 47,170 (89%) received at least one dose of CoronaVac and 2,656 individuals (5%) underwent RT-PCR testing from 19 January, 2021 to 13 April, 2021. Of 3,195 RT-PCR tests, 885 (28%) were positive. 393 and 418 case-control pairs were selected for the early and two-dose analyses, respectively, matched on calendar time, age, and neighbourhood. Among those who had received both vaccine doses before the RT-PCR sample collection date, the average time from second dose to sample collection date was 14 days (IQR 7-24). In the early analysis, vaccination with at least one dose was associated with a 0.50-fold reduction (adjusted vaccine effectiveness (VE), 49.6%, 95% CI 11.3 to 71.4) in the odds of symptomatic SARS-CoV-2 infection during the period 14 days or more after receiving the first dose. However, we estimated low effectiveness (adjusted VE 36.8%, 95% CI -54.9 to 74.2) of the two-dose schedule against symptomatic SARS-CoV-2 infection during the period 14 days or more after receiving the second dose. A finding that vaccinated individuals were much more likely to be infected than unvaccinated individuals in the period 0-13 days after first dose (aOR 2.11, 95% CI 1.36-3.27) suggests that unmeasured confounding led to downward bias in the vaccine effectiveness estimate. Interpretation: Evidence from this test-negative study of the effectiveness of CoronaVac was mixed, and likely affected by bias in this setting. Administration of at least one vaccine dose showed effectiveness against symptomatic SARS-CoV-2 infection in the setting of epidemic Gamma variant transmission. However, the low estimated effectiveness of the two-dose schedule underscores the need to maintain non-pharmaceutical interventions while vaccination campaigns with CoronaVac are being implemented. Funding: Fundação Oswaldo Cruz (Fiocruz); Municipal Health Secretary of Manaus; Fundação de Vigilância em Saúde do Amazonas. Competing Interests: We declare no competing interests. (© 2021 The Authors. Published by Elsevier Ltd.)
Databáze:	MEDLINE
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