studies, transmission, group O immunity?

[Mis à jour le mardi 24 novembre à 16h02] It was already known that older age, diabetes, or an underlying respiratory or cardiovascular disease can increase the risk of developing severe form of coronavirus infection. Blood group could also be a risk factor for COVID-19. In any case, this is what several scientific studies report. The assumptions to date.

► In March 2020, a first statistical study * published on the scientific pre-publication site “MedRxiv” and conducted by Chinese researchers from Shenzhen University showed that:

• People in group O would have done it 33% less risk of being contaminated from the new coronavirus compared to people in groups B and AB.
• People in Group A would have done it a 20% increased risk be contaminated with the novel coronavirus compared to people in groups B and AB.
• These two hypotheses appear to be valid regardless of the sex or age of the individual studied. “At the individual level, this does not change the need for protection, but at the population level it is interesting“, considers Jacques le Pendu, immunologist and director of Inserm research on Ouest France.

► In June 2020, a second study, Posted in The New England Journal of Medicine, carried out on 1,980 people with Covid-19, obtained the same results: a greater risk of contracting Covid-19 in blood group A compared to other blood groups and a protective effect in blood group O compared to other blood groups.

“The relationship between blood group and the risk of contracting the virus is now established “

“It was there in everything eight preprints on this topic. As far as I know, six are now published in leading scientific journals“, points out Jacques le Pendu during an interview with Marianne. And to specify”For me, the relationship between blood group and the risk of contracting the virus is now established. If causation has not yet been proven, all these studies converge in their findings that blood groups O are less at risk than others.“.

► Of them new scientific studies The results of which were published Oct. 14 in the American Society of Hematology’s journal Blood Advances provide details on the link between blood group and severity of coronavirus infection.

→ The first study of 473,000 people who tested positive for Covid-19 showed that Danish COVID-19 patients with type O or B blood spent less time in an intensive care unit than their type A or AB counterparts . They also needed less mechanical breathing and dialysis because they suffered from less kidney failure.

→ The second study on 95 severely Covid-19 patients in a Vancouver (Canada) hospital between February and April 2020 also showed that patients with type O or B blood exceeded on average 4.5 days less in the intensive care unit compared to those with type A or AB blood who spent an average of 13.5 days in an intensive care unit.

Depending on our blood type, our blood develops different antibodies.

“This [résultat] no wonder. We found the same thing during a 2003 study on the SARS virus outbreak (coronavirus very close to Covid-19, ed)“, Jacques Le Pendu pointed out, this time to France Inter. In 2008, a French study published in Glycobiology in which Jacques Le Pendu had participated proposed a beginning of explanation. Depending on our blood type, our blood develops different antibodies. The plasma that makes up the blood contains anti-A and anti-B antibodies in people of group O, all rhs combined, which would represent a potential double defense against a virus, like Covid-19 for example. In contrast, the plasma of people in group A contains only one type of antibody (anti-B), which would be a single potential defense against a virus.

Of course, the results of these four studies should be taken with a grain of salt. In other words, not all people in Group A will necessarily be infected with the coronavirus. And vice versa, even the people of group O are not immune to Covid-19. “There is only a small rate of protection or risk of infection, which clearly indicates that many other factors are involved in this disease. More research is therefore needed to establish this link.“, comments Dr. Sakthivel Vaiyapuri, associate professor of pharmacology-cardiovascular and poisonous substances at the University of Reading in England. These findings could therefore constitute a further avenue of research for develop a coronavirus treatment or vaccine. In all cases, regardless of blood group, just the fact of respect barrier gestures helps minimize the risk of infection.

Blood work, prescribed by your doctor, is the simplest and most common way to find out your blood type. After your appointment in a laboratory or medical center, you will be given a blood group card showing whether you are A, B, AB or O and rhesus (+ or -). Please note that you can also know your blood type during the donation.

* Sources

– Relationship between ABO blood group and COVID-19 susceptibility, Medrxiv, 16 mats 2020. To obtain this result, the research team analyzed the health status and blood group of 2,173 people infected with Covid -19, from three hospitals in Wuhan and Shenzhen, 206 of which had died of infection with the new coronavirus. They then compared them to the health status and blood type of 3,694 Wuhan residents who had not been infected with the coronavirus.

– Inhibition of the interaction between the SARS-CoV Spike protein and its cellular receptor by anti-histo-blood group antibodies, Patrice Guillon, Décembre 2008, Glycobiology.

– Reduced prevalence of SARS-CoV-2 infection in the ABO O blood group, October 14, 2020, Blood Advances.