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Dr Gérald Kierzek (Medical Director)
While the Sars-Cov-2 virus is still circulating, some people continue to escape its contamination. They are called Novid, for No or Never Covid, or people who have never contracted the disease. According to a new scientific study, this would be due to their genetic heritage.
Four years after the appearance of Covid-19, some people have never been infected by the virus. How can this phenomenon be explained? According to a study published in the journal Naturethis is explained by the particular genetic heritage of these people.
A study with only 16 participants
To better understand this phenomenon, scientists gathered a cohort of sixteen patients. The virus was deliberately inoculated into them in order to understand how their bodies reacted in response. Result:
- six patients had prolonged infection;
- three of them had a milder infection;
- and seven, or just under half, have never contracted Covid-19.
A specific gene helps eliminate the virus
By analyzing the genetic heritage of these patients who had never contracted the disease, the researchers understood that they immediately eliminated the virus thanks to a specific gene, HLA-DQA2, present in large quantities in their bodies. According to one of the lead authors of the study, this discovery constitutes a new basis for developing treatments or vaccines.
What are the possible immune explanations for this non-infection?
When asked, Dr. Gérald Kierzek is not surprised and analyzes the different immune explanations that can explain the natural resistance of these patients against the virus. Here is what could explain it:
- Strengthened innate immunity : “Some people may have particularly effective innate immune systems that can eliminate the virus before it can establish itself and replicate enough to cause a detectable infection.” exposes Dr Gérald Kierzek;
- Cross-immunity with “prior exposure to other coronavirus (such as those responsible for certain colds) which could have generated partial immunity against Sars-CoV-2″ ;
- Genetic peculiarities of which “Some individuals may have genetic variations that make them naturally less susceptible to infection, for example by altering the receptors the virus uses to enter cells” our expert further explains;
- A T cell responsebecause “even in the absence of detectable antibodies, some people may have developed a strong cellular immune response (via T lymphocytes) capable of rapidly neutralizing the virus” ;
- And finally, non-immune factors, “as the composition of the respiratory microbiome or anatomical peculiarities of the respiratory tract could also play a role” concludes the doctor, who recalls that the “Covid is a syndemic (an interweaving of diseases and biological factors, Editor’s note) which acts on a strong or weak immune system” and “prevention through its reinforcement is therefore essential.”