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A gene mutation that causes asymptomatic COVID

A new study seems to show that people with a particular gene have a much higher chance of having asymptomatic COVID-19. This gene seems to produce proteins that effectively destroy the SARS-CoV-2 virus that causes COVID-19.

I caught COVID-19, but I did not have any severe symptoms. I only actually determined that I had the disease because I had a stuffy nose, and I wanted to use the COVID-19 test kits that I had. I didn’t want them to go to waste. I had the vaccine plus four boosters, so I assume that the vaccines protected me. But with this study, it could be a combination of the vaccines, and I have the lucky gene.

As I usually do, I am going to review this new study and critique it. I hope some of you find it interesting in trying to figure out why some people get hit with severe symptoms of COVID-19 and some do not. It’s in the genes!

woman wearing face mask
Photo by Anna Shvets on

COVID-19 and the HLA gene paper

In a paper published in August 2023 in Nature, Jill Hollenbach, Ph.D., MPH, Weill Institute for Neurosciences, Department of Neurology, and Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, and colleagues used a cohort study to try to determine why at least 20% of individuals infected with SARS-CoV-2 remained asymptomatic.

This 20%, often referred to as “super dodgers,” appear to have a mutation in the immune system-supporting human leukocyte antigen (HLA) gene, which allows virus-killing cells to correctly and quickly identify SARS-CoV-2. These virus-killing cells, called T cells, were able to find the virus even if it was the first encounter due to a resemblance to already familiar seasonal cold viruses.

In other words, the HLA gene mutation allowed the T cells to cross-react with the SARS-CoV-2 virus as if it were a common cold virus. It is as if the T cells were already programmed to attack the COVID-19 virus. According to a press release about this study from the University of California San Francisco, having the HLA gene mutation “doesn’t prevent the virus from infecting cells but, rather, prevents people from developing any symptoms. That includes a runny nose or even a barely noticeable sore throat,”

Here are some of the key results.

  • Researchers found the mutation was carried by about 10% of the study’s population (nearly 30,000 individuals).
  • Having two copies of the genes increased the chances of being asymptomatic by over 8 times.
  • The HLA gene mutation did not prevent infection, it just stopped the SARS-CoV-2 virus from expressing even minor symptoms.


I like when science begins to solve mysteries, and one of the big mysteries was why some people seemed to avoid COVID-19, especially its most severe symptoms. Without a doubt, most people with mild symptoms, or who did not catch COVID-19, were a result of vaccines and boosters.

However, it is absolutely fascinating that there is a relatively common gene mutation that increased the chance of being asymptomatic for the disease.

Based on the design of this study, I give this study 4.5 out of 5 stars. It may not completely solve the puzzle of super dodgers, but it gives us powerful data as to what may cause it.


Michael Simpson
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