Common genetic defect protects from COVID symptoms

All those patients who tested positive for COVID but never exhibited symptoms may finally have an answer as to why.

A study from researchers at the University of North Carolina, University of California, and La Trobe University in Australia found that a common genetic variation that occurs in 10% of the population is responsible for mediating SARS-CoV-2 asymptomatic infection. People with this variant don’t feel sick when infected. The research was published in Nature.

The researchers hypothesized that there might be specific human leukocyte antigens that would help protect people from COVID or possibly make them more susceptible, because these genes code for proteins used in the immune system to help the body distinguish healthy cells from those infected by bacteria and viruses.

Those with the HLA-B*15:01 variant were much more likely to remain asymptomatic after infection. The researchers said the variant allows the immune system to react very quickly to the infection and eliminate it before symptoms appeared.

The report notes that subjects with the variant showed immunological memory against COVID without ever being exposed to the virus. The authors said that seasonal coronaviruses in the form of colds trained the body to rapidly react to a similar – albeit far more serious – coronavirus.

The researchers plan further investigation into the response against the virus, which will result in better COVID-19 treatments and vaccines.