Mary Horowitz, scientific chief at the Center for International Blood and Marrow Transplant Research. There are four main blood types - A, B, AB and O - and “it’s determined by proteins on the surface of your red blood cells,” said Dr. Being older or male seems to increase risk, and scientists have been looking at genes as another possible “host factor” that influences disease severity. Many researchers have been hunting for clues as to why some people infected with the coronavirus get very ill and others, less so. Most genetic studies like this are much larger, so it would be important to see if other scientists can look at other groups of patients to see if they find the same links, Topol said. They also tied blood groups to possible risk.

Researchers tied variations in six genes to the likelihood of severe disease, including some that could have a role in how vulnerable people are to the virus. The study, involving scientists in Italy, Spain, Denmark, Germany and other countries, compared about 2,000 patients with severe COVID-19 to several thousand other people who were healthy or who had only mild or no symptoms. Eric Topol, head of the Scripps Research Translational Institute in San Diego. it isn’t enough of a signal to be sure,” said Dr. The evidence of a role for blood type is “tentative. With the new work, “now I believe it,” he said.

Parameswar Hari, a blood specialist at the Medical College of Wisconsin, said of the report from China. “Most of us discounted it because it was a very crude study,” Dr.

Wednesday’s report in the New England Journal of Medicine does not prove a blood type connection, but it does confirm a previous report from China of such a link. Scientists who compared the genes of thousands of patients in Europe found that those who had Type A blood were more likely to have severe disease while those with Type O were less likely. A genetic analysis of COVID-19 patients suggests that blood type might influence whether someone develops severe disease.

B negative blood type and covid risk