August 10, 2023
Your Genes Could Be Protecting You from COVID
If you’ve managed to escape COVID’s clutches so far, your genes might be the reason. A recent study conducted at the University of California, San Francisco reveals that people with a particular genetic variation of a protein called human leukocyte antigen (HLA) may have a higher chance of never developing COVID symptoms, even if they get infected with the virus.
What is HLA?
HLA functions as a security guard on the surface of your cells, always on the lookout for trouble. When a virus tries to invade your cells, HLA steps up to the plate and tells your immune system to take action.
But here’s the fascinating part: HLAs are not identical for everyone. They are unique and distinct due to tiny differences on the genetic level.
How was this discovered?
The researchers behind this study, led by Professor Jill Hollenbach from the University of California, San Francisco, looked at data from a national bone marrow donor database. They examined the genetic sequences of HLAs in almost 1,500 people who had tested positive for COVID.
Around 136 individuals who were infected with COVID never showed any symptoms. It turns out that 20% of these asymptomatic individuals had at least one copy of a specific variant called HLA-B*15:01. On the other hand, only 9% of those who had symptoms had this variant.
The genetic code that tells your cells how to build HLAs can have slight changes, leading to different variants. You get two copies of the HLA gene, one from each parent. In fact, the study stated, “Individuals carrying two copies of HLA-B*15:01 are more than eight times more likely to remain asymptomatic than individuals carrying other genotypes.” So, if you have two copies of HLA-B*15:01, you’re more than eight times likelier to test positive for COVID but remain symptom-free.
Was the study representative?
The study focused mainly on people who identify as white, as there was more data available for this group. However, the researchers believe that this gene variant might also have the same effect on Black individuals stating in the study published in Nature magazine that, “we find that our results for HLA-B*15:01 appear to trend similarly in Black individuals, although this result is less clear in Asian and Hispanic individuals.” As stated in the study, the gene’s effects on Asian, Hispanic, and American Indian/Alaska Native populations aren’t entirely clear yet.
This study took place before vaccinates were available and therefore had limitations, including the lack of diverse representation, but it does illuminate how genes play a role in our vulnerability to viruses. Vaccination is still our most proven form of defense. So, whether your genes offer you some protection or not, getting vaccinated remains crucial to safeguarding yourself and those around you.
Always asymptomatic? If you never get sick from Covid, it could be in your genes (nbcnews.com)
A common allele of HLA is associated with asymptomatic SARS-CoV-2 infection | Nature