COVID-19: BCG As Therapeutic Vaccine, Transmission Limitation, and Immunoglobulin Enhancement

To date, there is no vaccine or treatment with proven efficiency against COVID-19, and the transmissibility of the SARS-CoV-2 virus can be inferred by its identification in the oro-nasopharynx. The bacillus Calmette Guérin (BCG) has the potential for cross-protection against viral infections. This study evaluates the impact of previous (priming effect, from the titer of anti-BCG interferon-gamma) or current BCG exposure (boost with intradermal vaccine) on 1) clinical evolution of COVID-19; 2) elimination of SARS-CoV-2 at different times and disease phenotypes; and 3) seroconversion rate and titration (anti-SARS-CoV-2 IgA, IgM, and IgG).