Novel coronavirus disease-19 (COVID-19) has spread worldwide, and to date presence of the virus has been recorded in 215 countries contributing 0.43 million of death. The role of blood groups in susceptibility/resistance to various infectious diseases has been reported. However, the association of blood groups with susceptibility to COVID-19 infections or related death are limited. In the present report, we performed an epidemiological investigation in the Indian population to decipher the importance of blood groups concerning susceptibility or mortality in COVID-19 infection.

Data on COVID-19 infection and mortality was obtained from the website of the Government of India. Prevalence of ABO blood groups in different states and union territories of India were searched using different databases such as PubMed and Google Scholar. Relevant articles were downloaded, and data were extracted. Spearman's rank coefficient analysis was employed to study the correlation between blood group frequencies and COVID-19 infection or mortality rate.

A significant inverse correlation was observed between the frequency of O blood group and the COVID-19 mortality rate (Spearman r=−0.36, P=0.03), indicating a possible protective role of O blood group against COVID-19 related death. In contrast, the prevalence of blood group B was positively correlated with COVID-19 death/million (Spearman r=0.67, P<0.0001), suggesting B blood type as a deleterious factor in COVID-19 infection.

ABO blood group system is associated with poor prognosis of COVID-19 infection. Blood group O may protects, and subjects with blood type B could be susceptible to COVID-19 mortality. However, further studies on COVID-19 infected patients in different population are required to validate our findings.