Query Response

Responder: Allison (Covid 19 Expert)

As far back as March, Chinese researchers analyzed blood types in 2,173 infected individuals from Wuhan and Shenzhen, and compared those results with surveys of blood types from healthy populations in the same region. They found that 38 percent of the covid-19 patients had Type A blood, compared to just 31 percent of the healthy people surveyed. By contrast, Type O blood seemed to lead to a reduced risk, with 26 percent of the infected cases versus 34 percent of healthy people. And Type A patients accounted for the largest proportion of covid-related deaths than any other blood type. Another study at Columbia University found similar trends: Type A individuals were 34 percent more likely to test positive for the coronavirus, while having Type O or AB blood individuals had a lower probability of testing positive. None of these studies were peer reviewed. But one that was, a genome study published in the New England Journal of Medicine on June 17, looked at genetic data from more than 1,600 hospitalized covid-19 patients in Italy and Spain, comparing their genes to 2,200 uninfected individuals. Those researchers found two gene variants in two regions of the genome associated with a bigger likelihood of severe covid-19 symptoms—including one region that determines blood type. Overall, patients with Type A blood had a 45 percent increased risk of experiencing respiratory failure after contracting covid-19, while those with Type O had a 35 percent reduction in risk. It’s completely unknown yet what would cause this. The authors of the NEJM study hypothesize that the proteins that define Type A and B blood might affect the immune system’s production of antibodies. The genes that determine blood type might have something to do with the ACE2 receptor that the coronavirus uses to infect human cells. In any case, blood type doesn’t seem to be among any of the more significant risk factors that distinguish mild cases from severe ones.