BCG vaccination and its possible effects on the acceleration of incidence and mortality by the new coronavirus: first step

Introduction: BCG vaccine (bacillus Calmette–Guérin) has been developed against tuberculosis and proven to be used for other purposes by activating and/or training innate immunity. The protective effect against the new coronavirus should be investigated and tested while a specific vaccine is not available. Objective: To compare the acceleration rates of incidence and lethality of COVID-19 according to the vaccination program for BCG of the main countries affected by the pandemic. Methods: Part one of three of the data survey from official sources on the number of cases and number of deaths by COVID-19 between December 31, 2019 and April 11, 2020, being calculated the incidence, mortality and lethality acceleration rates, and compared among predefined groups according to their BCG vaccination programs. Results: Countries without a vaccination program in place or that never had one for BCG had incidence and mortality acceleration rates of 21.36 and 53.21 times higher (p < 0.001), respectively, than the same rates in countries with a universal vaccination program. In addition, patients with an expanded vaccination program had a 43% lower mortality rate (p < 0.001) compared to countries with a vaccination program at birth only. Conclusion: There is a correlation between the coverage of BCG vaccination programs and the acceleration in the number of new cases and deaths in countries, showing a possible protective factor in places with existing BCG vaccination programs.