Could blood groups influence COVID-19 disease severity?


Biological factors that determine susceptibility to SARS-CoV-2 and severity of COVID-19 are yet to be fully understood. A pre-print released in medRxiv by Zhao et al suggests that the ABO blood grouping may influence acquisition of COVID-19 and severity of the disease. In this retrospective data review, individuals with blood group A were found to have a 20% increased risk of acquiring the COVID-19-causing virus (OR 1.20; CI 1.02-1.43) compared to non-A individuals. Individuals with blood group O had a lower risk of viral infection (OR 0.67; CI 0.60-0.75) compared to non-O individuals.

Among Wuhan Jinyintan Hospital patients, blood group O was also associated with a lower risk of mortality compared to blood group A, which was associated with a 48% increased risk of mortality.

Opinion piece in the Conversation by emphasises that more studies need to be done, and these results should not lead to changes in clinical management. 

“To date, we don’t have robust scientific evidence to prove that our blood group has a direct relationship with COVID-19 infection. In this observational study, if they considered several other parameters, such as the previous history of other – specifically immune or respiratory-related – diseases, the conclusions might have been different. They have also not explained why they failed to see a significant difference between the blood groups in the Shenzhen hospital. And given COVID-19 is a pandemic, the sample size that they have analysed is not sufficient to draw firm conclusions.

Journal Article: Zhao et al. Relationship between the ABO Blood Group and the COVID-19 Susceptibility

Article by Kenneth Omollo

International Union of Immunological SocietiesUniversity of South AfricaInstitute of Infectious Disease and Molecular MedicineScience Education PrizesElizabeth Glazer Pediatric Aids Foundation