Indirect effectiveness of a novel SARS-COV-2 vaccine (SCB-2019) in unvaccinated household contacts in the Philippines: A cluster randomised analysis.

Autor: Aziz AB; International Vaccine Institute, Seoul 08826, Republic of Korea., Sugimoto JD; International Vaccine Institute, Seoul 08826, Republic of Korea; Department of Epidemiology, University of Washington, 3980 15th Ave NE, Seattle, WA, USA; Vaccine and Infectious Disease Division, Fred Hutchinson Research Center, 1100 Fairview Avenue N., Seattle, WA, USA., Hong SL; International Vaccine Institute, Seoul 08826, Republic of Korea., You YA; International Vaccine Institute, Seoul 08826, Republic of Korea., Bravo L; University of the Philippines Manila, Ermita, Manila, Philippines., Roa C Jr; Manila Doctors Hospital, Manila, Philippines., Borja-Tabora C; Asian Hospital and Medical Center, Alabang, Muntinlupa, Philippines., Montellano MEB; Far Eastern University Hospital - Nicanor Reyes Medical Foundation, Quezon City, Philippines., Carlos J; Las Pinas Doctors Hospital, Las Pinas City, Philippines., de Los Reyes MRA; Las Pinas Doctors Hospital, Las Pinas City, Philippines., Alberto ER; Tropical Disease Foundation, Cavite City, Philippines., Salvani-Bautista M; University of the East Ramon Magsaysay Memorial Medical Center, Quezon City, Philippines., Kim HY; International Vaccine Institute, Seoul 08826, Republic of Korea., Njau I; International Vaccine Institute, Seoul 08826, Republic of Korea., Clemens R; International Vaccine Institute, Seoul 08826, Republic of Korea., Marks F; International Vaccine Institute, Seoul 08826, Republic of Korea; Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge CB2 0AW, United Kingdom; Heidelberg Institute of Global Health, University of Heidelberg, Im Neuenheimer Feld 130/3, 69120 Heidelberg, Germany; Madagascar Institute for Vaccine Research, University of Antananarivo, 3HM2+QH7, Antananarivo, Madagascar., Tadesse BT; International Vaccine Institute, Seoul 08826, Republic of Korea; Heidelberg Institute of Global Health, University of Heidelberg, Im Neuenheimer Feld 130/3, 69120 Heidelberg, Germany. Electronic address: Birkneh.Tadesse@ivi.int.
Jazyk: angličtina
Zdroj: The Journal of infection [J Infect] 2024 Oct; Vol. 89 (4), pp. 106260. Date of Electronic Publication: 2024 Aug 30.
DOI: 10.1016/j.jinf.2024.106260
Abstrakt: Background: Though observational evidence supports indirect effects of SARS-CoV-2 vaccines, randomised experiments are lacking. To address this gap, the double-blinded, prospective follow-up of the household contacts (HHCs) of Philippine participants of the individually-randomised, placebo-controlled trial of the adjuvanted-subunit protein COVID-19 vaccine, SCB-2019, (EudraCT, 2020-004272-17; ClinicalTrials.gov, NCT04672395) was analyzed in a cluster-randomised fashion.
Methods: Over an eight-week period, HHCs were followed by rRT-PCR and paired rapid antibody tests (RATs) to detect symptomatic (SCI, primary) and all (ACI, secondary) SARS-CoV-2 infection. A standard analysis estimated the indirect effectiveness of SCB-2019 for each endpoint, excluding HHC RAT-positive at enrollment. A secondary analysis employed enzyme-linked immunosorbent assay (ELISA) results to correct for suspected bias.
Findings: SCB-2019 (N = 3470) and placebo (N = 3225) exposed HHCs contributed to at least one analysis. The standard analysis estimated that SCB-2019 reduced the risk of SCI by 83% (95% confidence/credible interval [CI: 32% to 96%), with no effect against ACI. The bias-corrected relative risk reduction was 97% (95% CI: 74% to 100%) for SCI and 79% (95% CI: 14% to 96%) for ACI, with an estimated one SARS-CoV-2 infection prevented per 4.8 households where one member received SCB-2019.
Interpretation: SCB-2019 demonstrated bias-corrected indirect effectiveness against SARS-CoV-2 infection among HHC, even at a modest coverage level in the household (approximately 25%). Further research into the indirect effects of SARS-CoV-2 vaccines is needed to optimize the impact of limited doses in low and middle-income settings.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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