Interpreting the Results of Trials of BCG Vaccination for Protection Against COVID-19

Overview

Journal J Infect Dis

Publisher Oxford University Press

Specialty Infectious Diseases

Date 2023 Aug 9

PMID 37558650

Authors

Christie C A Noble

Nicole L Messina

Laure F Pittet

Nigel Curtis

Affiliations

Soon will be listed here.

Abstract

BCG vaccination has beneficial off-target ("nonspecific") effects on nonmycobacterial infections. On this premise, trials set out to investigate whether BCG provides off-target protection against coronavirus disease 2019 (COVID-19). A literature search identified 11 randomized "BCG COVID-19" trials, with conflicting results. These trials and the differences in their study design are discussed using the PICOT (participants, intervention, control, outcome, and timing) framework to highlight the factors that likely explain their inconsistent findings. These include participant age, sex and comorbid conditions, BCG vaccination strain and dose, outcome measure and duration of follow-up. Understanding how to control these factors to best exploit BCG's off-target effects will be important in designing future trials and intervention strategies.

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