Is it possible to be resistant to Covid-19? Well, according to some researchers, there are some people who have not yet been infected with Covid-19. This group of people are called super-resistant to the virus.
The study shows which signs and factors lead these people to not have been infected by SARS-Cov2-2. According to it, about 20% of these people had some type of genetic mutation, such as the production of a substance that defends against the virus.
These results are essential to understand how this group of people survived unscathed through a pandemic that, to a greater or lesser degree, likely came into contact with everyone in the world. According to geneticist Salmo Raskin, it is possible to identify the variants of the genetic material that protect these people and, from that, consider the development of preventive measures against the worsening of Covid-19.
The discovery of T cells
Like the research in Nature Magazine, the study was based on healthcare professionals who had daily contact with people infected with the virus, but who did not become infected. Therefore, the entire immune system of these people was observed. Blood tests showed that despite not being infected with Covid-19, these professionals had protective T cells.
But what are these T cells? Well, according to the research, it is a defense and protection mechanism that recognizes and eliminates cells infected by Covid-19.
T cells remain immune for many years, in addition to identifying the virus and, most importantly, creating the immune system’s ability to develop these protective cells.
The discovery of these cells is essential to understand how part of this social group was not infected during the long two years of the pandemic.
Discordant couples
Another study by the University of São Paulo – USP analyzed the issue from the point of view of discordant couples, in which one person catches the virus, but the other does not. That is, one does not infect the other.
The results showed that people who were not infected by the Coronavirus have a greater activation of defense cells, better known as natural killer (NK) cells. This type of cell works as a defense barrier against infections.
Blood type
The relationship between contagion and blood type is also studied. Research done in China showed that people with blood type A appeared to be more likely to contract the virus. In contrast, people with type O had a lower risk.
However, as these are still initial studies, it is not yet known what confers this protective effect or how it actually occurs. One of the main criticisms of the study is that factors such as age and comorbidities were not considered.
Lack of receivers
Finally, there are people who are naturally more resistant because they have rare types of receptors. The receptors are responsible for installing the virus inside the cell.
Some recent studies have shown that there are people with genetic mutations that make the ACE2 receptor not work, which reduces the risk of infection.
For infectologist Celso Granato, clinical director of Grupo Fleury, one of the explanations for people with superimmunity is precisely the lack of this receptor. This prevents the infection from taking hold or the body from reacting robustly.
This phenomenon already happens in other viral infections. Thus, Granato believes that studies on the subject can be useful to combat other diseases.
For example, knowledge already produced on the subject, specifically in the 1990s, made it possible to create drugs for the treatment of AIDS.
More questions than answers
In conclusion, it is possible to notice that there are more questions than answers. That’s because the virus is relatively new and most studies are still ongoing.
A team of international researchers is producing a study that analyzes what genetically differentiates resistant individuals.
The main difficulty is precisely to find these resistant people. The expectation is in the couples mentioned above, where one contracted the disease and the other did not, and in health professionals who were not infected throughout the pandemic. Currently, 700 volunteers are enrolled and 5,000 are under review.
Once potential participants are identified, their genomes will be compared with those of people who have been infected to understand the differences. All this, in search of the genes responsible for the resistance to the disease.
With all these studies, it will finally be possible to develop new drugs and better public health guidelines to mitigate the future impacts of the coronavirus.