New COVID-19 studies have suggested that there is a weak link between a person's blood type and coronavirus infection, going against the preliminary studies that indicate blood type may be a significant risk factor in who is more likely to get infected and who would be severely affected by the viral infection.
New Studies Reject Preliminary Studies
In a report by the New York Times, two new studies did not find any evidence that people with Type A blood have an increased risk of getting COVID-19.
The two new studies are from Columbia Presbyterian Hospital in New York and one from the Massachusetts General Hospital, who observed thousands of new coronavirus patients over the past few months.
Nevertheless, they did find some evidence that blood type O might be less likely to have coronavirus, but the effect is so small that they are not counting it.
"No one should think they're protected," said Dr. Nicholas Tatonetti, a data scientist from Columbia University.
Dr. Tatonetti, along with Michael Zeitz, a graduate student, looked over the medical records of 7,770 people tested positive of COVID-19 in the past few months during the pandemic and found that people who were Type A have a somehow lower risk of being placed on ventilators.
Meanwhile, those with type AB are at higher risk--nevertheless, the researchers did say the data may not be reliable as only a few patients on their record have this blood type.
The initial results of Dr. Tatonetti and Zietz's study from 1,559 COVID-19 patients were published on preprint service medRXiv in April 2020, with their larger survey being reviewed for publication in a scientific journal.
Blood Type Should Not be Considered
The other study from Massachusetts General Hospital did find some evidence that people with Type O blood are slightly less likely to be infected with COVID-19 but other than they, they did not find any other link between a person's blood type and how likely they are going to be put under ventilators or their odds of dying.
According to Dr. Anahita Dua, a vascular surgeon and the senior author of the study said that she would not be considering the patient's blood type when judging their risk and even said, "I wouldn't bring it up."
"With this new paper, it's probably decided that blood groups are not influencing the outcome of the disease," said Joern Bullerdiek, who is the director of the Institute for Medical Genetics at the University of Medicine Rostock in Germany.
Nevertheless, Zietz did find some interesting possibilities relating to COVID-19 and a person's blood type, saying that there is some sort of evidence that "certain blood types have different risks of clotting."
Unfortunately, Dr. Tatonetti and Zietz have a hard time finding many coronavirus patients for the study in New York, but others may take the challenge and help understand the nature of the virus more.
Blood types do influence how the body's immune system fights infection, for instance, those with Type A create different kinds of antibodies compared to Type B, but based on the current studies, there isn't enough evidence linking COVID-19 infection to blood types.