"Trained immunity" from Mycobacterium spp. exposure or BCG vaccination and COVID-19 outcomes.

ABSTRACT: Protective variables for Coronavirus Disease 2019 (COVID-19) are unknown. "Trained immunity" of the populace as a result of Bacille Calmette-Guérin (BCG) vaccination policy implementation and coverage had been suggested to be one of the factors responsible for the differential impact of COVID-19 on different countries. Several trials are underway to evaluate the potential protective role of BCG vaccination in COVID-19. However, the lack of clarity on the use of appropriate controls concerning the measures of "trained immunity" or the heterologous cell-mediated immunity conferred by BCG vaccination has been a cause of concern leading to more confusion as exemplified by a recently concluded trial in Israel that failed to find any protective correlation with regard to BCG vaccination. Whereas

SUBMITTER: Singh S 

PROVIDER: S-EPMC7595322 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature