Since its origin in the Wuhan province of China in December 2019, Coronavirus Disease 19
(COVID-19) has spread to most parts of the world and has infected millions of people. However, the
significant variability in the mortality rate across the world indicates some underlying factors, especially
the immunity factors that may have a potential role in this variability. One such factor that is being
discussed and tested is the Bacillus Calmette-Guerin (BCG) vaccine. The available evidence suggests
that BCG vaccination provides broad protection against respiratory infections as well as other infections.
Therefore, BCG may prove to be a barrier for COVID-19 infection and may offer a ray of
hope. In this review, we contrasted BCG vaccination program with COVID-19 mortality and analyzed
trained immunity and cross protection against unrelated pathogens due to BCG vaccination. On analyzing
the available data, we observed that countries without universal BCG vaccination policy are
severely affected, while countries having universal BCG policies are less affected. Based on these data,
we propose that the SARS-CoV-2 related qualified immunity, cross protection against unrelated pathogens
and COVID-19 impact variations could be partly explained by the different national policies regarding
BCG childhood vaccination. The combination of reduced morbidity and mortality may make
BCG vaccination a potential new tool in the fight against COVID-19.