New Study Finds Causal Link Between Blood Type and COVID-19 Severity

More than 5 million people have died due to COVID-19. Although vaccines have provided good protection, it is important to fully understand the biology behind the severe forms of COVID-19. 

Severe COVID-19 commonly requires hospitalization and intensive care with assisted respiratory support, and respiratory failure is the most common reason for COVID-19 associated mortality 

New Study Findings 

In a new study, researchers investigated more than 3,000 blood proteins and whether or not they had any relationship with the severity of SARS-CoV-2 infection.  The study was published in the journal Plos Genetics.

The researchers used mendelian randomization to assess the relationship between the gene variants in the blood proteins and COVID-19 disease outcomes. 

In the blood group protein group, using genetic instruments and under the assumptions of Mendelian randomization, the findings were consistent with ABO being causally associated with both an increased risk of hospitalization as well as the requirement of respiratory support or death by COVID-19. The risk is likely to be higher in individuals with A, B or AB blood types. They also found an association between blood type A and a higher mortality. 

Previous studies in 2020 pointed to a correlation between blood type and the risk of serious illness from SARS-CoV-2 infection. The results from this study had the same conclusions. The researchers concluded that type A blood type has a link with higher risk of hospitalization and the need of respiratory support or death.


Alish B. Palmos, et al. Proteome-wide Mendelian randomization identifies causal links between blood proteins and severe COVID-19. Plos Genetics. 2022. 

Image from: 

Photo by Fusion Medical Animation on Unsplash