throughout the covid-19 pandemic some people were infected but did not show symptoms. A new study published in Nature shows that a genetic variation common would be responsible for the asymptomatic infection by SARS-Cov-2.
The research coordinated by the University of North Carolina (USA) focused on a group of genes called human leukocyte antigens (HLA), which is essential for the immune response and highly variable between individuals.
Those genes encode proteins used by the immune system to identify healthy cells and distinguish them from those infected by bacteria and viruses.
Individuals with the HLA-B*15:01 genetic variant, which occurs in approximately 10% of the population, were much more likely to remain asymptomatic after infection.
The team’s hypothesis was that your immune system might react “so quickly and powerfully that the virus was killed before it caused any symptoms”highlighted the university in a note.
The study used cells from people with HLA-B*15:01 who donated blood several years before the pandemic and the results showed that they had memory T lymphocytes (in charge of locating the infected cell and destroying it) against a specific SARS-CoV-2 particle.
That immunological memory would cause a much faster response and would explain why these individuals remained asymptomatic.
One question to be answered was how this immunological memory against SARS-CoV-2 could be developed without having been exposed to the virus that causes covid19.
The authors noted that other types of coronaviruses have caused seasonal colds for decades, so they estimated that these people were exposed to them in the past.
Somehow, people who specifically carried HLA-B*15:01 could rapidly kill SARS-CoV-2-infected cells due to cross-reactive immune responses.
After analyzing the genomic sequences of all coronaviruses, the study showed that this SARS-CoV-2 particle recognized by HLA-B*15:01 in unexposed individuals is very similar to viral particles from other previous coronaviruses.
That is, those people created an immunological memory for the previous coronaviruses, but because of the great similarity of that viral particle, their memory T cells can also recognize and kill SARS-CoV-2 very quickly.
Source: EFE
Source: Gestion
Ricardo is a renowned author and journalist, known for his exceptional writing on top-news stories. He currently works as a writer at the 247 News Agency, where he is known for his ability to deliver breaking news and insightful analysis on the most pressing issues of the day.
