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COVID symptoms seem to never touch certain people — and researchers may have finally figured out why

Heart condition POTS may be linked to COVID
Heart condition POTS may be linked to COVID 02:01

A new study is giving us insight into "super dodgers," people who contract COVID-19 but never develop symptoms, and what sets them apart.

Researchers say this group may have a genetic advantage, finding that they're more than twice as likely as those who become symptomatic to carry a specific gene variation that helps them destroy the SARS-CoV-2 virus. The study is published in the journal Nature,

Studies have shown about 20% of people infected with COVID avoid severe sickness, the researchers note. These "super dodgers" appear to have a mutation in the immune system-supporting human leukocyte antigen, allowing virus-killing cells to identify the coronavirus, according to the study. These virus-killing cells, called T cells, were able to find the coronavirus even if it was the first encounter due to a resemblance to already familiar seasonal cold viruses.

"If you have an army that's able to recognize the enemy early, that's a huge advantage," Dr. Jill Hollenbach, the study's lead researcher, a professor of neurology, epidemiology and biostatistics and a member of the Weill Institute for Neurosciences at UCSF, said in a news release. "It's like having soldiers that are prepared for battle and already know what to look for, and that these are the bad guys."

Researchers found the mutation was carried by about 10% of the study's population and having two copies of the variant further increased protection from feeling sick by more than eight times.

"It 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," according to the release.

Understanding the biology behind asymptomatic infection has "important implications for public health measures, vaccine design and therapeutic development," the authors wrote.

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