Adaptive immunity induced by Bacillus Calmette-Guérin and its relationship with COVID-19.

Abstract

ABSTRACT

COVID-19, caused by SARS-CoV-2, has been a worrying factor in mortality worldwide, so several innovative approaches are being developed to slow the spread of SARS-CoV-2. In particular, BCG, the tuberculosis vaccine, is being considered as an alternative therapeutic modality. BCG vaccine is known to induce both humoral and adaptive immunity, thus activating non-specific and cross-reactive immune responses in the host, which in combination could effectively resist other pathogens, including SARS-CoV-2. In this review we intend to describe based on the review of the literature; if prior BCG vaccination influences the mortality rates of COVID-19, thus seeking to expand scientific knowledge, in addition to stating whether it will contribute to the fight against COVID-19, and may be ideal in this context due to its low cost, and wide distribution. The literature suggests that there is a lower mortality rate in countries with a prolonged national BCG vaccination program, and this also contributes to reducing infant and adult mortality rates over 45 years of age, mediated by non-specific immunity.