The findings of two studies published this Wednesday in Blood Advances, the journal of the American Society of Hematology, suggest that people with type O blood are less vulnerable to infection with the new coronavirus – and, once infected, are less likely to develop serious complications associated with Covid-19.
The work, developed by Danish and Canadian scientists, strengthens a third study, published in June in the New England Journal of Medicine, which had already discovered genetic information, both in patients with Covid-19 and in healthy people, which pointed out in the same sense – while those with blood type A seemed to be more at risk of being infected with the new coronavirus, the opposite was true for those with type O.
Good news for those with type O blood? They may be, but in addition to the need to investigate more and gather more statistical data on the subject, “this does not replace other severity risk factors such as age and comorbidities, ”explained this Thursday to CNN Mypinder Sekhon, an intensive care physician at Vancouver General Hospital, a professor in the Department of Medicine at the University of British Columbia and one of the authors of the Canadian study.
If you have type A blood, you don’t need to start panicking. And if you are type O, you are not free to go to pubs and bars ”, he insisted on emphasizing.
The Canadian study looked at 95 critically ill patients with Covid-19 and found that, of those who needed ventilators to breathe, 84% had type A or AB blood – this in a universe of patients in which blood groups O and B were the majority (61%).
The Danish study revealed that among a total of 7,422 people who tested positive for the new coronavirus, only 38.4% were blood type O – in a universe of 2.2 million healthy (or untested) people, the percentage of the population with blood O was 41.7%. On the other hand, 44% of people in the sample with type A blood tested positive – in the control population the blood group represents 42.4%.
“We don’t know if it’s some kind of group O protection, or if it’s some kind of vulnerability in the other blood groups“Torben Barington, a professor at the University Hospital of Odense and the University of Southern Denmark and the lead author of the study, told that channel.
I think this is of scientific interest, and when we find out what the mechanism is, we may be able to use it proactively when it comes to treatment. ”
Although there are several theories, the researchers have not yet been able to determine what is the link between the different blood groups and Covid-19.
To CNN, Mypinder Sekhon suggested that the key may lie in the clotting factors – because people with type O blood are less prone to blood clotting problems, which have been one of the factors most often associated with Covid-19 complications. Other hypotheses involve blood group antigens and how they may or may not affect the production of antibodies to fight infection; or the genetic markers associated with each of the blood types and the way they act on immune system receptors.
“We have to understand the mechanism and understand it at the molecular level so that we can say with certainty why this is happening – that it really is type O blood and not anything that can be associated with it in any way”, warned Amesh Adalja, a researcher at Johns Hopkins University, unrelated to any of the studies. “I think we’ve seen enough to realize that this is really an important question that the investigation must answer. There is more science to do here, but it seems to me that there is more and more evidence accumulated on this hypothesis. ”