When these antigens come into contact with a pathogen or other unfamiliar substance, they trigger an immune system response. One explanation: Your blood type is based on proteins, called antigens, that cover the surface of your red blood cells. Blood type may also influence norovirus susceptibility. Research has shown that people with type O blood are more likely to get seriously ill from cholera than others who come down with the illness and type O blood has been shown to offer some protection against severe malaria. Michael's Hospital in Toronto and lead author of the study published in Annals of Internal Medicine. “There's a fairly decent amount of existing literature beyond SARS-CoV-2” that certain blood types can play a role in disease risk and severity, says Joel Ray, M.D., a clinician scientist and professor at St. The blood type–infection connection is not unique to the coronavirus. Blood type may influence other infections, as well Most of the value in the research, Silverstein says, is to learn more about the new virus that has so far infected almost 68 million people worldwide, and how the body responds to it. “They are at risk for COVID, just a little bit lower than type A.… That doesn't mean that O is zero risk.” 'I would never tell someone who is type O that they don't have to wear a mask, or they don't have to do social distancing, or they don't have to wash their hands frequently,” says Roy Silverstein, M.D., professor and chair of medicine at the Medical College of Wisconsin Division of Hematology and Oncology, who was not involved in the studies. And several other peer-reviewed studies reinforce these findings.Įven still, experts caution that the accumulating evidence on this subject shouldn't influence everyday medical or public health decisions. They also observed that individuals with type O blood had a slightly lower risk for getting severely ill or dying from COVID-19 if they did become infected. They found that people with type O blood had a lower risk for contracting the coronavirus (SARS-CoV-2) compared to those with type A, B or AB. Canadian researchers reached a similar finding in their retrospective study published in Annals of Internal Medicine. Researchers in Denmark found that among more than 7,400 people who tested positive for COVID-19, fewer individuals had type O blood compared to type A, despite the fact that the two blood types accounted for the same share of the population when compared to a larger control group. This, however, does not mean they can't contract the virus or fall seriously ill from it. It is the presence of A and B antigens and corresponding antibodies that determines your ABO blood group.En español | In the last several months, a number of studies have drawn a connection between blood type and COVID-19 risk, and most have reached the same conclusion: People with type O blood, the most common kind, may have a slight advantage over their peers when it comes to risk for a coronavirus infection and hospitalization or death from COVID-19. That’s why giving someone blood from the wrong ABO group can be life-threatening. They recognise any ‘foreign’ antigens and tell your immune system to destroy them. You also have antibodies in the clear part of blood called plasma.Īntibodies are important in transfusion because they are the body’s natural defence system. Which group you belong to depends on the antigens and antibodies in your blood.Īntigens are a combination of sugars and proteins that coat the surface of a red blood cell.ĭepending on your combination, you will have: There are four main blood groups in the ABO group system.Įach group is important and we need donors from every group to ensure we have the right blood for the people who need it. The ABO group system gives the letter part of your blood type and Rh system gives the positive or negative part. The two most important blood group systems for transfusion are ABO and Rh. Your blood group is inherited from genes passed on by your parents.

Blood type percentages