O Is for Optimal
I thought everyone had suffered through Covid at least once. But not these two people I know through work. They both also mentioned that they have type O negative blood. This couldn’t be a coincidence.
Several studies have now shown that people with blood type O are less susceptible to contracting Covid, and those with blood type A are more likely to get it.
In the early days of the pandemic, those findings were hotly debated. But one study this summer described the mechanism by which Covid interacts with blood cells. It found that part of the spike protein — the matchstick-like structures sticking out of the surface of the virus — more effectively binds to group A cells and less so to group O cells.
“Now we have a scientific explanation,” says Katrine Wallace, an epidemiologist at the School of Public Health of the University of Illinois at Chicago. This could help future research to develop vaccines or treatments, she says.
Even Rh factor, the + or – displayed after your blood type, matters. Some testing even found that those with Rh-negative blood appear to be at decreased risk of infection. While that’s been less conclusive, it fit perfectly with my very unscientific finding that the only people I know in the world who never had Covid have type O negative blood.
Since we can’t change our blood types, how should this affect the way we go about our lives?
Public policy experts say that everyone should get vaccinated no matter what blood type they have. One study found blood group A may be 20% more likely to be infected after exposure than blood group O, but that factors such as age and chronic conditions like heart disease rank higher than blood type in determining an individual’s risk for severe infection.
In fact, there doesn’t appear to be a relationship between blood type and Covid’s severity or mortality rate, according to one article that compiled various research efforts.
“At the moment it’s an interesting biological phenomenon for sure, but it doesn’t have any implications that can be communicated to the average person and change their behavior in any way,” says William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center in Nashville. — Nacha Cattan
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