Ever wondered how some people manage to evade the symptoms of COVID-19 even after they contract the virus? A new study says a certain gene mutation helps them to be super dodgers.
Researchers from the University of California-San Francisco have found the first evidence for a genetic basis for asymptomatic SARS-CoV-2. The secret is in the gene mutations of human leukocyte antigen (HLA) called HLA alleles, according to the findings of the study, published in the journal Nature.
HLA are the protein markers that play a key role in the body’s defense against infectious diseases. Earlier studies have shown how susceptibility and progression of infections such as hepatitis B virus and HIV differed in people with differences in the HLA alleles.
The latest study identified an HLA allele, known as HLA-B*15:01, that makes people asymptomatic to infection from COVID-19.
The study included 29,947 participants from the National Marrow Donor Program in the US. Using a mobile app, researchers screened the participants for COVID-19 and checked if they were experiencing any symptoms. The study was conducted during the early stages of the pandemic before vaccines were readily available.
At the end of the study in April 2021, 1,428 participants tested positive for COVID-19, of which 136 remained asymptomatic. The gene mutation HLA-B*15:01 was seen in about 10% of the study’s population.
The findings suggest that 20% of the participants who were asymptomatic to the infection had at least one copy of the HLA-B*15:01, while only 9% of those who reported symptoms had the gene mutation. In people with two copies of the variant, the likelihood of being asymptomatic to COVID infection was more than eight times.
The mutation does not mean they will be free from contracting the virus. Researchers say it just prevents them from developing any noticeable symptoms.
“If you have an army that’s able to recognize the enemy early, that’s a huge advantage. It’s like having soldiers that are prepared for battle and already know what to look for, and that these are the bad guys,” study lead Jill Hollenbach said in a news release.
Researchers believe the findings will help in developing new treatments or vaccines in the future.
“By studying their immune response, this might enable us to identify new ways of promoting immune protection against SARS-CoV-2 that could be used in future development of vaccine or drugs,” said Stephanie Gras, a professor and laboratory head at La Trobe University.
Published by Medicaldaily.com