The international BRACE trial assessed the BCG vaccine, originally designed to prevent tuberculosis, for efficacy against COVID-19 among healthcare workers. The study, conducted by the Murdoch Children’s Research Institute, found that the BCG vaccine did not significantly reduce the risk of COVID-19 infection. Among nearly 4,000 participants, symptomatic infections occurred more frequently in the BCG group (14.7%) compared to the placebo group (12.3%) during the first six months. The trial’s limitations included a lower-than-expected recruitment of participants due to the rapid rollout of COVID-19 vaccines, which restricted analysis on severe outcomes like hospitalization and death.
Nonetheless, the findings suggest that while BCG may not prevent symptomatic COVID-19, it could enhance the immune response, potentially offering quicker recovery from the illness. Future research will investigate BCG’s broader impacts against other viral infections and its role in enhancing responses to COVID-19 vaccines. The trial, supported by substantial philanthropic funding, underscores the importance of large-scale studies in evaluating vaccine efficacy in emergencies. Further results on BCG’s effects are anticipated later this year, aiming to clarify its benefits beyond tuberculosis prevention.
