Journal Article

Efficacy of BCG vaccination on incidence, severity and clinical progression of COVID-19: A BCG-REVAC population analysis

Pereira, Marcos, de Souza, Ramon Andrade, Genser, Bernd, Ichihara, Maria Yury, Barreto, Maurício Lima, da Natividade, Marcio Santos, Pereira, Susan Martins, de Jesus Lima, Carla Cristina Oliveira, Barreto, Florisneide Rodrigues, de Castro, Daniel Barros, Rodrigues, Laura Cunha, de Souza Teles Santos, Carlos Antônio

2025

Overview

Can vaccination with Bacille Calmette-Guérin prevent clinical progression of COVID-19? Data from the BCG-REVAC trial was archived in a database, creating an excellent opportunity to link it to notified cases of COVID-19 to evaluate the efficacy of BCG against incidence, severity and clinical progression to severe COVID-19 when given at birth day, at school age as a first dose or as a second dose. This study was conducted in the population of the BCG-REVAC cluster randomisation trial including 354,403 schoolchildren, aged 7 to 14 years, from 767 schools from two cities, Salvador and Manaus. Cases of COVID-19 from the System for Notification of Infectious Diseases and the System for Notification of Severe Respiratory Illnesses were record linked to BCG-REVAC population. The exposure was Vaccination or revaccination obtained by the BCG-REVAC. The outcomes of interest in this study were incidence COVID-19; incidence of severe COVID-19; and clinical progression of COVID-19. This project was approved by the Ethics Committee of the Institute of Collective Health, Federal University of Bahia, Brazil. The neonatal dose and a first dose of BCG at school age protect against the incidence of severe COVID-19 in multivariate models, whose efficacies were 30 % (95 %CI:1–51) and 64 % (95 %CI: 22–84), respectively. The neonatal dose showed an effect on severe clinical progression of symptomatic COVID-19 disease in COVID-19 infected subjects 39 % (95 %CI:11 % - 58 %). Even 23 years after BCG vaccination and revaccination of school-age children our results suggesting a protective effect of BCG first dose against incidence of severe COVID-19 in infected individuals, a smaller effect of the neonatal dose and no effect of the second dose at school age.

• Publisher: Elsevier Ltd,Elsevier Limited
• Subject: Adolescent / Adult / Age / Allergy and Immunology / Bacillus Calmette-Guerin vaccine / Bacillus Calmette-Guérin / BCG / BCG Vaccine - administration & dosage / BCG Vaccine - immunology / Brazil / Brazil - epidemiology / Child / Clinical trials / Cluster Analysis / Comparative analysis / Coronaviruses / COVID-19 / COVID-19 - epidemiology / COVID-19 - immunology / COVID-19 - prevention & control / COVID-19 infection / COVID-19 vaccines / Disease Progression / Effectiveness / Efficacy / ethics / Female / Follow-Up Studies / Humans / Immunization / Immunization, Secondary / Incidence / Infections / Infectious diseases / Intensive care / Male / Neonates / Population studies / protective effect / Respiratory diseases / SARS-CoV-2 - immunology / SARS-CoV − 2 / Schools / Severity / Severity of Illness Index / Tuberculosis / Tuberculosis, Pulmonary - prevention & control / Vaccination / Vaccination - methods / Vaccination - statistics & numerical data / Vaccine Efficacy / vaccines / Viral infections