BCG vaccination as protection from COVID-19: epidemiological and molecular biological aspects

The article presents a review of the recent hypothesis that the national policy of BCG-vaccination affects the spread of COVID-19 in different countries. It contains the information from 70 publications with epidemiological indicators, providing pros and cons of this hypothesis, with the description of possible mechanisms of non-specific antiviral action of BCG vaccine. It is concluded that there are not enough data to verify or refute the hypothesis, and at the moment the use of BCG vaccine to prevent the spread of the infection even in high-risk groups would be unreasonable.