Association of Bacillus Calmette Guerin Vaccine Strains with COVID-19 Morbidity and Mortality - Evaluation of Global Data.

Abstract

Background:Literature suggests that the presence of the current Bacillus Calmette Guerin (BCG) policy appears to mitigate COVID-19 disease burden but no information exists on the nature of the BCG strain and disease burden.Objectives:To study the association between type of BCG strain, BCG coverage (%), and COVID-19 disease burden.Methodology:An audit of global data on strains and disease burden was done. Country-specific data for COVID-19 cases and deaths, BCG-related data, and income level were obtained from the online databases, and the association was analyzed using linear regression.Results:Data of 139 countries were studied and 117 (84%) had a current BCG policy. Data on BCG strains were available for 51 countries and 18/51 (35%) used the Danish strain. While the choice of strain did not impact COVID-19-related disease burden, the presence of a current BCG policy was significantly associated with lower COVID-19 mortality.Conclusion:The presence of current BCG policy is associated with decreased COVID-19-related disease burden, but the type of strain used by a country in its vaccination program does not impact disease burden.