Further Evidence of a Possible Correlation Between the Severity of Covid-19 and BCG Immunization

Serge Dolgikh

All countries in the VL category currently have a UIP or had it recently still covering most of age cohorts. Majority of countries in the L category have an ongoing UIP or had it relatively recently or in limited use (e.g. Canada, Norway for targeted groups). No countries from group C (never had a UIP or significant BCG immunization program) are found in the groups VL, L with lower impacts of Covid-19 though regional variations are possible (e.g. Canada). In some cases of the group H that had a vaccination program at some point, the lower effectiveness can be explained by a conjecture that the protection against Covid-19 has higher effectiveness if the vaccine is given at birth or at a young age (see the next observation).