July 20, 2023 – It seems that being a COVID-19 “super imposter” isn't necessarily just luck. It's genetic.
Scientists have found that many individuals who didn't have COVID symptoms became infected but had a genetic mutation that trained the immune system to mount a stronger response to the virus since it noticed similarities to the common cold.
The results were published on Wednesday within the journal Nature.
An estimated 20% of individuals infected with COVID don't have any symptoms, previous research shows. This latest study found that individuals who carried a genetic mutation called HLA-B*15:01 were greater than twice as prone to don't have any symptoms as people within the study who didn't have the mutation. The researchers called the HLA-B*15:01 mutation “common” and estimated that 1 in 10 people have it.
For the study, researchers used data from a bone marrow donor registry because bone marrow matching also relies on HLA genetic information. They recruited 30,000 people from the bone marrow donor registry to make use of a mobile app developed by the University of California-San Francisco to trace COVID status throughout the first 12 months of the pandemic, when many individuals were getting routine COVID tests, akin to for work or resulting from possible exposure.
When the genetic mutation was detected in people without symptoms, one other Australian research team found that the mutation was linked to immune system T cells that mount a rapid and effective response to SARS-CoV-2, the virus that causes COVID. The response suggested pre-existing immunity, akin to an immune system trained after responding to similar viruses.
Pre-existing immunity, which gave the impression to be resulting from the immune system having previously fought off seasonal colds, was present even in individuals who had neither been vaccinated against SARS-CoV-2 nor previously infected with it.
“By studying their immune response, we may be able to identify new ways to promote immune protection against SARS-CoV-2 that could be used in future vaccine or drug development,” said researcher Stephanie Gras, PhD, professor and laboratory director at La Trobe University in Australia, in a opinion.