London: People with blood type O may have a lower risk of infection from the SARS-CoV-2 virus, that causes Covid-19, and reduced likelihood of severe outcomes, including organ complications, if they develop the disease, two new studies suggest. The studies, published in the journal Blood Advances on Wednesday, add evidence that there may be an association between blood type and vulnerability to Covid-19. However, the researchers noted that more studies are needed to better understand why and what it means for patients.
In the first study, researchers compared Danish health registry data from over 473,000 individuals tested for Covid-19 to data from a control group of more than 2.2 million people from the general population. Among the Covid-19 positive, they found fewer people with blood type O and more people with A, B, and AB types. The study suggests that people with blood types A, B, or AB may be more likely to be infected with Covid-19 than people with type O.
The researchers did not find any significant difference in rate of infection between A, B, and AB types. “It is very important to consider the proper control group because blood type prevalence may vary considerably in different ethnic groups and different countries,” said study author Torben Barington from University of Southern Denmark.
