Study uncovers direct link between blood group A and a higher risk for COVID-19 infection

Ask the average American what their blood type is, and you will likely receive a blank look. For most people, blood type only becomes an issue if they need a blood transfusion. Beginning in the earliest days of the COVID-19 pandemic, however, results from previous work published in Blood Advances suggested that people with blood group A (about a third of the U.S. population) seemed to be more vulnerable to infection with the novel coronavirus, while those with blood group O (about 38% of the population) seemed to be somewhat less susceptible. Until now, however, no study had identified a “smoking gun”—a mechanism that might explain this apparent risk imbalance.