Blood types and coronavirus: How many blood groups are there and what is the risk?

A study published by the New England Journal of Medicine has found that people with blood type A have a 45% higher risk of suffering severe effects of Covid-19 compared to people with other blood types. Meanwhile people with blood type O, the most common blood type, appear to be somewhat protected from the effects of the coronavirus compared to people with other blood types.

The study was published after genetic analysis was performed on more than 1,900 severely ill coronavirus patients in Spain, Italy, Denmark, Germany and other countries and compared to over 2,000 patients who were not sick. However, Wednesday’s report in the New England Journal of Medicine does not conclusively prove a blood type connection it merely confirmes that it may influence the course of the disease.

The report in the New England Journal of Medicine comes on the back of similar studies in China that suggested a link between bloody type and the way Covid-19 affects individiuals. “Most of us discounted [one of the Chinese studied] because it was a very crude study. Now I believe it, it could be very important,” said Dr. Parameswar Hari, a blood specialist at the Medical College of Wisconsin, about the report from China linking blood types with Covid-19.

Coronavirus reseachers hunt for clues

Most genetic researchers have been hunting for clues as to why some people infected with the coronavirus get very ill and others not so much. They came to the conclusion that being older seems to increase the risk, and scientists have been looking at genes as another possible “host-factor” that influences the coronavirus severity.

The main four blood types are: A, B, AB and O. According to the study, people with type O are better able to recognize certain proteins as foreign and that may extend to proteins on virus surfaces. Blood type also has been tied to susceptibility to some other infectious diseases.