For a long time, I heard that there is a relationship between different blood types and susceptibility to COVID-19 infection where type A people have higher chance of catching COVID-19 than type O people. This is an interesting article that debunks this theory about blood types.
A handful of studies have shown a link between blood type and the novel coronavirus, though most involved a small number of people and some were not peer reviewed.
A team of European researchers who published their findings in the New England Journal of Medicine in June found people with Type A blood had a 45% higher risk of becoming infected than people with other blood types, and people with Type O blood were just 65% as likely to become infected as people with other blood types. They studied more than 1,900 severely ill coronavirus patients in Spain and Italy, and compared them to 2,300 people who were not sick.
A similar effect for Hong Kong health care workers with blood group O was observed during the SARS outbreak, which infected 8,098 people from November 2002 to July 2003 and is from the same family of viruses.
This week’s study may counter some of that research. “We showed through a multi-institutional study that there is no reason to believe being a certain ABO blood type will lead to increased disease severity, which we defined as requiring intubation or leading to death,” said Dr. Anahita Dua of Mass General, who led the study team.
There are two hypotheses about the link between blood groups and Covid-19, said Jacques Le Pendu, research director at Inserm, a French medical research organization. One is that people with type O are less prone to coagulation problems and clotting has been a major driver of the severity of Covid-19.
He said it could also be explained by the likelihood that the virus will carry the infected person’s blood group antigen. As such, the antibodies produced by a person with blood group O might neutralize the virus when caught from a person with blood group A — similar to the rules for blood transfusions.
“However, this protection mechanism would not work in all situations. A blood group O person could infect another blood group O person for example,” he explained, adding that any protective effect is unlikely to be large and the amounts of antibodies are highly variable from person to person.
People with type A should not be alarmed, nor should people with type O relax, said Sakthivel Vaiyapuri, an associate professor in cardiovascular and venom pharmacology at the University of Reading in the UK.
Vaiyapuri, in collaboration with Thi-Qar University in Iraq, is conducting a study into the role of blood types based on data from more than 4,000 people in Iraq who had Covid-19 and 4,000 who didn’t get sick. He said that early results suggest type O might have a protective effect, but it’s not definitive. And given how very many underlying variables there are, any effect, protective or otherwise, is likely to be quite small.
This article also tells about the work of blood types and reason for their existence. For the entire article go to https://www.cnn.com/2020/07/16/health/blood-types-coronavirus-wellness-scn/index.html.