These blood types may be susceptible to COVID-19

Blood type has little impact on daily life. In fact, most people do not even know if they are type A, B, AB, or O. But this seemingly trivial detail may be a factor in the global tyranny of 2020, i.e., those who come under the control of the coronavirus.

A new study published in Blood Advances (open in new tab) confirms what researchers have seen for some time: people with blood type A are at very high risk of contracting COVID-19 (open in new tab), while people with type O O-type people seem to be protected from COVID-19.

Chinese researchers (open in new tab) first shared this idea in March, and a month later a Columbia University paper (open in new tab) published similar results. Among the 750,000 people (the largest study population ever) who were diagnosed and hospitalized with COVID-19, those with type O were found to be more protected (opens in new tab).

A subsequent peer-reviewed study published in the New England Journal of Medicine (open in new tab) confirmed this idea: people with type A were 45% more likely to be infected with COVID-19 than people with other blood types, while people with type O were 35% less likely.

"It's clear that type O is somewhat preventable; it's not a matter of being type A or B, it's a matter of not being type O," says Mark Wooden, MD, professor of hematology and oncology at Baylor College of Medicine in Houston. [A study in the NEJM reports that people with type A blood are also more likely to have respiratory failure.

However, a Columbia University study found no difference in intubation or death and blood type. In addition, a recently published study in the Annals of Hematology (open in new tab) specifically examined the association between blood type and the need for intubation and death in patients with confirmed COVID-19. The results showed no association between blood type and severity of illness. A new study in Blood Advances, mentioned above, found similar results. While questions about this new disease continue to abound, another small study, also published in Blood Advances (open in new tab), suggested that blood type A or AB was associated with a higher risk of certain intense interventions and longer ICU stays, although the researchers themselves said the association was considered "unresolved" at this time.

Why people with type O are more protected is not known, but there are many theories.

The most basic idea is that blood type may affect a person's ability to fight viruses, says David Aronoff, M.D., director of infectious diseases at Vanderbilt University Medical Center in Nashville. It may affect the strength of the immune system and the inflammatory response to infection.

In any case, he explains, it affects not only how susceptible you are to the virus, but also how intense your symptoms (open in new tab) are. [19] [20] However, the NEJM article emphasizes, however, that different blood types produce different antibodies. If you are type O," Dr. Wooden says, "you naturally produce antibodies against types A and B. These type A antibodies may make it more difficult for SARS-CoV-2 to attach to its receptors in type O blood and multiply in the body, Dr. Wooden explains.

However, there is another interesting layer of potential protective elements in type O blood. It is called von Willebrand factor, a glycoprotein responsible for repairing vascular damage by coagulating blood.

We know that the COVID-19 virus damages the inner lining of blood vessels. The body then releases VWF (von Willebrand factor) into the blood to repair the damage to the vessel wall. However, VWF also promotes blood clotting. [We know that there is a virus-induced coagulation problem in COVID-19 patients who have died because they have an unusually high incidence of stroke, renal failure, pulmonary embolism, and other coagulation problems," says Dr. Wooden. [A recent analysis published in the Lancet (open in new tab) showed that compared to COVID-19 patients who were not in the intensive care unit, patients who became critically ill and died in the intensive care unit had higher levels of VWF antigen in their blood.

And wow, people with type A blood naturally have higher levels of VWF than people with type O blood, Dr. Wooden noted. Furthermore, black people, who die at disproportionately high rates from COVID-19, tend to have higher levels of VWF as well.

Being type O does not necessarily mean you don't have a problem. All previous studies have only looked at blood types associated with symptomatic cases of coronavirus, Dr. Aronoff noted. [i.e., type O, like type A, may be unknowingly transmitting the virus to others.

"There are two possibilities: type O may not be infected with the virus because it has no viral landing strip.

"Or, being type O, the virus does enter, but the A antibodies prevent it from docking with enough cells to cause disease. But the virus still remains in the body and can infect others."

No, the blood type is actually quite weak, says Dr. Wooden.

Socioeconomic status is a major weakness, requiring one to work outside the home, work in crowded buildings, or live in smaller quarters with more family members.

Second, age and health status are likely to be affected. Being older or having an underlying medical condition such as cancer, diabetes, or heart disease increases the likelihood of a severe case of coronavirus, Dr. Wooden adds.

Blood type is after all of these.

[21] People with blood type O may be slightly more protected from the virus, and people with type A may be slightly more vulnerable. However, as far as we know, everyone is at risk of contracting the virus and becoming an asymptomatic carrier.

The discovery of the protective effects of type O is crucial to understanding how the virus works.

However, both Drs. agree that it should not actually change anyone's behavior.

"I'm type O, but I'm not going to go in and out of bars just because of this slight preventive effect," Dr. Wooden says.

"These findings do not change your behavior. Anyone can get SARS-CoV-2 and be caught in a chain of infection," Dr. Aronoff adds. [The safest and most effective way to prevent contracting the coronavirus and unknowingly infecting others is to wear a mask (opens in new tab) and keep your social distance, regardless of your blood type.

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