Mortality due to COVID-19 in different countries is associated with their demographic character and prevalence of autoimmunity

In the first few months of its deadly spread across the world, COVID-19 mortality has exhibited a wide range of variability across different nations. In order to explain this phenomenon empirically, we have taken into consideration all publicly available data for 106 countries on parameters like demography, prevalence of communicable and non-communicable diseases, BCG vaccination status, sanitation parameters, etc. We used multivariate linear regression models and found that the incidence of communicable diseases correlated negatively. Demography, improved hygiene and higher incidence of autoimmune disorders correlated positively with COVID-19 mortality and they were among the most plausible factors to explain COVID-19 mortality compared to GDP of the nations.