A new study suggests that an individual’s blood type may play a role in their chances of contracting the coronavirus.
Published in the New England Journal of Medicine, it saw scientists analyze the genetic information of 1,980 patients who tested positive for the coronavirus across seven hospitals between Italy and Spain, where significant transmission occurred.
Controlling for confounding variables like population discrepancies and outliers, 835 patients and 1,255 control participants from Italy were included, along with 775 patients and 950 control participants from Spain.
The results indicated that a 45 percent higher risk of infection was associated with patients who had the blood type A versus other blood types. Similarly, researchers identified a “protective effect” in patients with type O blood.
Results hinged on a DNA cluster observed at a specific chromosome, which scientists say have functions that “are potentially relevant to COVID-19.” The study also notes, however, that a causative gene cannot be accurately named based on this evidence alone. Additionally, due to the constrained time frame during which the study was conducted, some confounding variables were not controlled for, including underlying cardiovascular and metabolic conditions.
Roy Silverstein, a hematologist at the Medical College of Wisconsin, told MarketWatch that the DNA cluster is found in other parts of the body, so blood types may not totally predict an individual’s risk of contracting the coronavirus.
“Those who are not type A should not interpret this study to mean that they can let their guard down,” Silverstein explained. “Similarly, the data are not yet convincing enough to recommend that those with Type A need to do even more than what is recommended.”
The report shares these concerns, stating that further research into findings linking blood types with coronavirus infections is needed. In short: correlation does not indicate causation.
“Everyone needs to pay attention to COVID-19 prevention by following well-accepted guidelines related to social distancing, face covering, hand-washing, and self-isolation and testing in the setting of possible COVID-related symptoms,” Silverstein concluded.