For the vast majority of people, contracting COVID-19 means a whirlwind of symptoms ranging from the relatively mild to the deadly serious. However, there’s also a portion of the population who have contracted the illness but never develop symptoms. While the reason why has eluded scientists and doctors since the start of the pandemic, new research might point to a genetic reason.
A study published Wednesday in the journal Nature suggests a mutation in a specific gene might prevent people from developing COVID symptoms. The findings could eventually lead to the development of new therapies and vaccines to treat the disease.
The gene is a protein marker called the human leukocyte antigen (HLA). The mutation involved—called HLA-B*15:01—helps T cells, which are used by the immune system to get rid of viruses, better identify coronavirus even if it’s never encountered it via a vaccine or previous infection before.
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“If you have an army that’s able to recognize the enemy early, that’s a huge advantage,” lead author Jilly Hollenbach, a professor of neurology at the University of California, San Francisco, said in a statement. “It’s like having soldiers that are prepared for battle and already know what to look for, and that these are the bad guys.”
The study’s authors recruited roughly 1,500 unvaccinated individuals. Of this cohort, 136 tested positive for COVID-19 sometime between February 2020 and the end of April 2021—but remained completely asymptomatic. The study’s authors discovered that 20 percent of these individuals had at least one copy of the HLA variant. Meanwhile, 9 percent of those who reported symptoms had the variant. The participants who had two copies of the variant were eight times more likely to be asymptomatic.
Looking further into the participants’ T cells, the team discovered that the cells responded to a unique signature in the novel coronavirus that allowed it to quickly identify and attack the virus.
"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," co-author Stephanie Gras, a professor and laboratory head at La Trobe University, said in a statement.
However, the authors did note that a big limitation of the paper was its lack of diversity; the study was limited to people who self-identified as white because the study respondents didn’t have enough people of other ethnic and racial groups.
As such, the findings should be taken with a grain of salt—especially by people of color, who are often left out when it comes to drug and treatment development. Future research would require a more diverse array of participants in order to gain a fuller understanding of the role HLA plays in protecting our bodies against the virus.
Doing so could unlock an entirely new way of fighting the virus. If our bodies can completely manage the infection without any debilitating and potentially life-altering symptoms, it would completely change the paradigm of the fight against COVID-19 as we know it.
