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

World Health Organization. Director General's Opening Remarks at the Media Briefing on COVID-19, https://covid19.who.int/2020 [accessed 09 September 2022]. Malik, 2020, BCG vaccine: a hope to control COVID-19 pandemic amid crisis, Hum Vaccin Immunother, 16, 2954, 10.1080/21645515.2020.1818522 Miller A, Raendelar MJ, Fasciglione K, Roumenova V, Li Y, Otazu GH. Correlation between universal BCG vaccination policy and reduced morbidity and mortality for COVID-19: an epidemiological study. medRxiv. 28 March 2020. https://www.medrxiv.org/content/10.1101/2020.03.24.20042937v1 [accessed 10 August 2022]. Covián, 2019, BCG-induced cross-protection and development of trained immunity: implication for vaccine design, Front Immunol, 10, 2806, 10.3389/fimmu.2019.02806 Khan, 2021, COVID-19 pandemic and vaccines update on challenges and resolutions, Front Cell Infect Microbiol, 11, 10.3389/fcimb.2021.690621 O'Neill, 2020, BCG-induced trained immunity: can it offer protection against COVID-19?, Nat Rev Immunol, 20, 335, 10.1038/s41577-020-0337-y Nankabirwa, 2015, Child survival and BCG vaccination: a community based prospective cohort study in Uganda, BMC Public Health, 15, 175, 10.1186/s12889-015-1497-8 Moorlag, 2019, Non-specific effects of BCG vaccine on viral infections, Clin Microbiol Infect, 25, 1473, 10.1016/j.cmi.2019.04.020 Adesanya, 2021, Bacillus Calmette-Guerin (BCG): the adroit vaccine, AIMS Microbiol, 7, 96, 10.3934/microbiol.2021007 Brasil. Inf Tecn Campanha Nac Vacinação Contra Covid, https://www.gov.br/saude/pt-br/coronavirus/notas-tecnicas/; 2021 [accessed 13 September 2022]. 2014 2020 Cox, 1972, Regression models and Life-Tables, J R Stat Soc, 34, 187 Giamarellos-Bourboulis, 2020, Activate: randomized clinical trial of BCG vaccination against infection in the elderly, Cell, 183, 315, 10.1016/j.cell.2020.08.051 Tsilika, 2022, ACTIVATE-2: a double-blind randomized trial of BCG vaccination against COVID19 in individuals at risk, Front Immunol, 13 Channappanavar, 2014, T cell-mediated immune response to respiratory coronaviruses, Immunol Res, 59, 118, 10.1007/s12026-014-8534-z Eggenhuizen, 2021, BCG vaccine derived peptides induce SARS-CoV-2 T cell cross-reactivity, Front Immunol, 12, 10.3389/fimmu.2021.692729 Nuovo, 2020, Strong homology between SARS-CoV-2 envelope protein and a Mycobacterium sp. antigen allows rapid diagnosis of Mycobacterial infections and may provide specific anti-SARS-CoV-2 immunity via the BCG vaccine, Ann Diagn Pathol, 48, 10.1016/j.anndiagpath.2020.151600 Dos Anjos, 2022, Efficacy and safety of BCG revaccination with M. bovis BCG Moscow to prevent COVID-19 infection in health care workers: a randomized Phase II clinical trial, Front Immunol, 13, 10.3389/fimmu.2022.841868 Rakshit S, Adiga V, Ahmed A, Parthiban C, Kumar N, et al. BCG revaccination qualitatively and quantitatively enhances SARS-CoV-2 spike-specific neutralizing antibody and T cell responses induced by the COVISHIELD vaccine in SARS-CoV-2 seronegative young Indian adults. Research Square. 02 March 2022. https://www.researchsquare.com/article/rs-1395683/v1. [accessed 28 August 2022]. Ramos-Martinez, 2021, Effect of BCG revaccination on occupationally exposed medical personnel vaccinated against SARS-CoV-2, Cells, 10, 3179, 10.3390/cells10113179 Czajka, 2022, Vaccines (Basel), 10, 314, 10.3390/vaccines10020314 Upton, 2022, Safety and efficacy of BCG re-vaccination in relation to COVID-19 morbidity in healthcare workers: a double-blind, randomised, controlled, phase 3 trial, EClinicalMedicine, 48, 10.1016/j.eclinm.2022.101414 Ritz, 2012, The influence of bacille calmette-guerin vaccine strain on the immune response against tuberculosis: a randomized trial, Am J Respir Crit Care Med, 185, 213, 10.1164/rccm.201104-0714OC Gupta, 2021, Positive QuantiFERON test and the severity of COVID-19 disease: a prospective study, Indian J Tuberc, 68, 474, 10.1016/j.ijtb.2020.12.013 Ward, 2021, Indeterminate QuantiFERON gold plus results reveal deficient interferon gamma responses in severely ill COVID-19 patients, J Clin Microbiol, 59, 10.1128/JCM.00811-21 Ten Doesschate, 2022, Bacillus Calmette-Guérin vaccine to reduce healthcare worker absenteeism in COVID-19 pandemic, a randomized controlled trial, Clin Microbiol Infect, 28, 1278, 10.1016/j.cmi.2022.04.009 Dionato, 2022, BCG vaccine safety in COVID-19 convalescent adults: BATTLE a randomized controlled trial, Vaccine, 40, 4603, 10.1016/j.vaccine.2022.06.039 Villanueva, 2022, Revaccination with Bacille Calmette-Guérin (BCG) is associated with an increased risk of abscess and lymphadenopathy, npj Vaccines, 7, 6, 10.1038/s41541-021-00421-5