- Early research has revealed a possible link between individuals’ blood type and their risk of coronavirus.
- Several preliminary studies found that people with type O blood have a lower risk of getting the coronavirus, or are less likely to develop a less serious infection if they get it.
- But that link is tenuous and should not be used to judge a patient’s risk: “No one should think they are protected,” said one expert.
- The research is divided into which blood types are associated with an increased risk of coronavirus infection.
- Visit the Business Insider home page for more stories.
A handful of initial studies have found that people with O blood type may have a slight advantage during this pandemic.
Research published over the weekend found that patients with type O were less likely to test positive for COVID-19 than patients with type A, B, or AB blood.
An April study found a similar trend: The research (although not yet peer-reviewed) looked at 1,559 coronavirus patients in New York City and found that a smaller proportion had type O blood.
Other research has reported a link between patients’ blood type and the severity of their infections, but these two studies did not. In general, the jury does not yet know if your blood type significantly affects your risk of coronavirus.
“No one should think they are protected,” Nicholas Tatonetti, lead author of the April study, told the New York Times.
Blood type O is associated ‘with a lower risk of testing positive’
The latest blood type study examined nearly 1,300 coronavirus patients admitted to five Massachusetts hospitals in March and April. The results showed that blood type O “was associated with a lower risk of testing positive,” the researchers said, while types B and AB were at increased risk. Type A blood had no link to a patient’s possibility of a positive diagnosis.
A hospital employee wearing protective equipment shows a cotton swab to collect a coronavirus sample.
Miguel Medina / AFP via Getty
The research is in line with previous findings.
In March, a study of 2,173 coronavirus patients at three hospitals in Wuhan and Shenzhen, China, also found that people with type O blood had a lower risk of infection.
A study published last month in the New England Journal of Medicine found an even more substantive link: patients in Italy and Spain with type O blood had a 50% lower risk of serious infection (cases requiring ventilation or supplemental oxygen) compared with patients with other blood types.
More specifically, the study authors discovered that a region of the participants’ genomes that helps encode blood type was linked to a patient’s chances of developing severe symptoms.
Research is divided on whether any blood type is associated with increased risk
Vials containing blood samples.
Phil Noble / Reuters
Or it is the most common blood type. About 48% of Americans have Type O blood, according to the Oklahoma Blood Institute.
In general, your blood type depends on the presence or absence of proteins called A and B antigens on the surface of red blood cells. People with O blood have no antigen. This genetic trait is inherited from our parents.
The New England Journal of Medicine study found that people with A antigens were 50% more likely to develop severe COVID-19 symptoms such as respiratory failure.
However, research on whether people with type A blood face an increased risk of infection does not give a clear idea.
The study in China found that patients with blood type A had a higher risk of infection compared to people with other blood types. The April research also found that a higher proportion of infected patients studied had blood type A. But the new study found that people with types B and AB were “more likely to test positive.”
A test for antibodies against the coronavirus.
Robin Utretcht / SOPA Images / LightRocket via Getty Images
Most researchers agree that it is too early to know whether there is a strong link between blood type and risk of infection.
Dr. Eric Topol, director of the Scripps Research Translational Institute, told the Associated Press last month that the evidence is “tentative … not enough of a sign to be sure.”
The link is so tenuous, in fact, that blood type shouldn’t be one of the factors you use to assess your risk, experts say.
“I wouldn’t even mention it,” Anahita Dua, co-author of the new study, told the New York Times.
