Persons with blood group O are at a lower risk of Covid-19 infection, suggests a new study published in the Journal of Infection in Developing Countries.¹

A meta-analysis of 18 retrospective observational trials sought to examine the chances of a Covid-positive patient to have a specific blood group based on the hypothesis that this may affect the dynamics of the pandemic according to the blood group distribution within the population. The studies were sourced from PubMed, Web of Science, MedRxiv, BioRxiv and Google Scholar databases. The meta-analysis included a total of 13,600 patients and 3,445,047 controls.

Persons having blood group O were found to be at a lower risk of acquiring Covid-19 infection (OR 0.76) compared to individuals with blood group A (OR 1.25) and AB (OR 1.13), who were at higher risk of the infection.

Since this meta-analysis included publications from different nations, researchers also analyzed the association of blood group type with Covid-19 among different populations. Among the European, Chinese and Eastern Mediterranean population, the association between blood group A, O and Covid-19 infection remained stable and showed no change. But among the American population, those having blood group B were at higher risk of Covid-19 compared to other blood groups (OR 1.21). The association of AB blood group with risk of Covid-19 was significant only among the European population (OR 1.41).

This meta-analysis has demonstrated a possible association between Covid-19 and ABO blood groups and identified persons with blood group O to be at less risk of becoming infected, while the risk of infection was greater for those with blood groups A and AB. According to the authors, their findings suggest that A and AB blood groups may possibly need to more strictly adhere to personal protective measures, they also recommend the need for more studies to further validate this association.

Reference

1. Huaqiang Wang, et al. ABO blood group influence COVID-19 infection: a meta-analysis. J Infect Dev Ctries. 2021 Dec 31;15(12):1801-1807. doi: 10.3855/jidc.13815.