Heredity, blood type and cross-immunity .. Why do some flee from Covid?

Heredity, blood type and cross-immunity .. Why do some flee from Covid?

On equal exposure, some pass between the drops and are surprised. Are they just lucky? Evidence is still lacking, but several methods have been put forward to try and explain their resistance to the virus.

blood type ?  Via immunity?  genetic predispositions?  Are there factors that protect some?
blood type ? Via immunity? genetic predispositions? Are there factors that protect some? © Getty

This is a phenomenon that doctors know. So they weren’t surprised. The head of the emergency service in the Paris region attests to this: “Out of about sixty doctors around me, who have treated and ‘breathed’ Covid for two years, a small group, but exposed like the others, have gone through droplets and never had Covid.”

Connection status but not contaminated

This discovery was not surprising, “We know we are not equal in the face of disease”, he explains. “Why do some people with HIV declare disease so quickly, while others live with the virus their whole lives without ever getting sick? In medicine, we know that genetic predispositions are at work, which we can’t explain,” He said.

“I’ve been in contact several times. (…) It’s a bit like passing between drops, because even if I’m careful, I don’t stop myself from living. Today, in living in Paris, two years later, not having the virus, it becomes rarer”, attested, for example, by Julian, thirty, to France International. After two years of a pandemic, especially weeks of Omicron, however much more contagious than Delta, the “survivors” of Covid, those who survived, are becoming increasingly rare and even tending to flee. They are amazed. Are they lucky or just cautious? put up?

Lucky, warned or asymptomatic?

Clearly there were those who were very careful, who rarely went out, or who had no children, and who were not in a position to catch him. There are also those who have contracted the Covid virus without knowing it. An asymptomatic form and who mistakenly thinks he has survived. For the rest, there are hypotheses, but little evidence so far. “Not everything is always explained.”, recognized infectious disease specialist. “We can catch it or not because at the moment we are more or less in good shape with a more or less efficient immune system. If you drink, if you smoke for example, if you are tired … everything can play.”

What about studies that said a few months ago that vitamin D could play a role? “It’s totally fictitious,” Immunologist explains. “We know that vitamin D is important for the proper functioning of the immune system, but that does not mean that taking vitamin D will prevent infection with the virus, beware of the easy shortcuts!”

The effect of blood type?

Another track: From 2020, we also mentioned the effect of blood type. Belonging to group O would reduce the risk of infection but also of dangerous forms, which has been concluded over several dozen studies, has been taken very seriously by Inserm in particular. This does not mean that people in group O pose no risk with respect to Covid and can overcome all precautions, it simply means that from a monitoring point of view, they appear to be less at risk than people in group A, for example.

The beginnings of a biological explanation have been put forward. Other genetic and immunological factors may be involved, Inserm also mentions without us being able to fully define or explain everything at this point.

Cross path immunity?

We talked about this at the beginning of the epidemic: catching colds due to coronaviruses will protect against infection with SARS-CoV-2. why ? Because our body will keep in its memory the defense that started at that time and will restart it. Setting aside for some time, this shared immunity hypothesis re-emerged a few days ago with a study by Imperial College London.

The study, which was conducted in the United Kingdom, followed 52 participants and then lived with an infected person and thus were exposed to the virus, through this closure. Half were infected, and the other half were not. In those who did not become infected, the researchers simply found a much higher level of pre-existing T cells. These T lymphocytes make up our immune memory, the ones that recognize and destroy infected cells.

The presence of these T lymphocytes tends to demonstrate that previous infection with other coronaviruses would have prepared the ground, thus protecting these subjects, who are already ready to fight another coronavirus. These T cells will not actually target the Sars-Cov barbed protein found on its surface, but other endogenous proteins common in coronaviruses. Our study provides the clearest evidence to date of this T cells caused by cold coronaviruses play a protective role against SARS-CoV-2 infection.”Professor Ajit Lalvani, co-author of the study, explained, adding that perhaps it is just a form of protection, which should not make it possible to overcome barrier or vaccine gestures.

Perhaps the beginning of the explanation. A possible course of prevention is also possible. The researchers concluded that new vaccines that target these common coronavirus proteins can stimulate a T-lymphocyte response. Thus we will have a kind of “universal” vaccine against coronaviruses. Indeed, laboratories, including Moderna, are already (among others) working on this path.

Leave a Comment

Your email address will not be published.