Genetics company 23andMe says a new study strengthens the idea that blood type is associated with coronavirus risk, although it’s not clear by how much and whether there’s any way for doctors to act on it.
Scientists at 23andMe looked at the DNA of more than 1 million people who have taken its DNA test. They found more than 15,000 who said they had a positive coronavirus test and 1,131 who said they were hospitalized.
The scientists said the data strengthens the evidence for a role for the ABO blood group system in Covid-19 host genetics.
“Our data supports a role in susceptibility to infection, suggesting that blood group O is protective in contrast to non-O blood groups,” the team wrote in a pre-print report on MedRxiv, which has not been reviewed by other experts. They did not say by how much, but other studies have found it is a very small factor.
Other factors: Far more important than blood type, however, are other factors, including obesity, which more than doubled the risk of hospitalization, the study found. Blacks and Latinos were also at higher risk than Whites – all findings that reflect what other studies have found.
Research limitations: There are many limitations to the research. 23andMe relies on people to report their own symptoms and test results. People who are most severely ill or who die would be unlikely to have their results recorded in the survey. Plus, the federal government says fewer than 10% of people who have been infected with coronavirus have been tested for it, so results are far from complete.