The effect of BCG vaccination on infection and antibody levels against SARS-CoV-2—The results of ProBCG: a multicenter randomized clinical trial in Brazil

• Published in: International journal of infectious diseases Vol. 130; pp. 8 - 16
• Main Authors: Santos, Ana Paula, Werneck, Guilherme Loureiro, Dalvi, Ana Paula Razal, dos Santos, Carla Conceição, Tierno, Paulo Fernando Guimarães Morando Marzocchi, Condelo, Hanna Silva, Macedo, Bruna, de Medeiros Leung, Janaina Aparecida, de Souza Nogueira, Jeane, Malvão, Ludmila, Galliez, Rafael, Aguiar, Roberta, Stefan, Roberto, Knackfuss, Sabrina Modena, da Silva, Elisangela Costa, Castineiras, Terezinha Marta Pereira Pinto, de Andrade Medronho, Roberto, e Silva, José Roberto Lapa, Alves, Rogério Lopes Rufino, de Moraes Sobrino Porto, Luís Cristóvão, Rodrigues, Luciana Silva, Kritski, Afrânio Lineu, de Queiroz Mello, Fernanda Carvalho
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.05.2023; The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases; Elsevier
• Subjects: BCG; BCG Vaccine; Brazil - epidemiology; ChAdOx1 nCoV-19; COVID-19; COVID-19 - epidemiology; COVID-19 - prevention & control; COVID-19 Vaccines; Humans; Immunoglobulin G; Mycobacterium bovis; Original article - Clinical Trial; SARS-CoV-2; Vaccination; Vaccine; Brazil; COVID-19; Vaccine; BCG
• ISSN: 1201-9712; 1878-3511
• DOI: 10.1016/j.ijid.2023.02.014

•Bacillus Calmette-Guérin (BCG) could be effective against SARS-CoV-2 based on the concept of trained immunity.•COVID-19 vaccines and BCG can enhance the immune response represented by immunoglobulin G levels.•The cumulative incidence of COVID-19 was smaller in BCG-vaccinated participants.•Immunoglobulin G levels tend to be higher and longer in the group submitted to BCG vaccination. Evatuate if Bacillus Calmette-Guérin (BCG) vaccine could be used as a tool against SARS-CoV-2 based on the concept of trained immunity. A multicenter, double-blinded, randomized clinical trial recruited health care workers (HCWs) in Brazil. The incidence rates of COVID-19, clinical manifestations, absenteeism, and adverse events among HCWs receiving BCG vaccine (Moreau or Moscow strains) or placebo were compared. BCG vaccine-mediated immune response before and after implementing specific vaccines for COVID-19 (CoronaVac or COVISHIELD) was analyzed. Cox proportional hazard and linear mixed effect modeling were used. A total of 264 volunteers were included for analysis (BCG = 134 and placebo = 130). The placebo group presented a COVID-19 cumulative incidence of 0.75% vs 0.52% of BCG. The Moreau strain also presented a higher incidence rate (1.60% × 0.22%). BCG did not show a protective hazard ratio against COVID-19. In addition, the log (immunoglobulin G) level against SARS-CoV-2 presented a higher increase in the BCG group, whether or not participants had COVID-19, but also without statistical significance. Our results suggest that BCG has a tendency of protection against SARS-CoV-2 and higher immunoglobulin G levels than placebo. The clinical trial was registered at https://clinicaltrials.gov/ (NCT04659941).