Bacillus Calmette-Guerin Vaccination as Defense Against SARS-CoV-2: A Randomized Controlled Trial to Protect Health Care Workers by Enhanced Trained Immune Responses

SARS-CoV-2 spreads rapidly throughout the world. A large epidemic would seriously challenge the available hospital capacity, and this would be augmented by infection of healthcare workers (HCW). Strategies to prevent infection and disease severity of HCW are, therefore, desperately needed to safeguard continuous patient care. Bacille Calmette-Guérin (BCG) is a vaccine against tuberculosis, with protective non-specific effects against other respiratory tract infections in in vitro and in vivo studies, and reported morbidity and mortality reductions as high as 70%. Furthermore, in our preliminary analysis, areas with existing BCG vaccination programs appear to have lower incidence and mortality from COVID191. The investigators hypothesize that BCG vaccination can reduce HCW infection and disease severity during the epidemic phase of SARS-CoV-2.