COVID-19 Genetic Risk Variant Downs Risk of Contracting HIV

Genetic heritage, apart from advanced age and chronic diseases contribute to individual COVID-19 severity risk.

Researchers studied new genetic risk variants in ancient human DNA and observed that its frequency had increased significantly since the last ice age.

Hence, it may have had a favorable impact on its carriers in the past. "This major genetic risk factor for COVID-19 is so common that I started wondering whether it might be good for something, such as protecting against another infectious disease", says Hugo Zeberg, who is the sole author of the new study in PNAS.

‘People who carried the risk factor for COVID-19 had fewer CCR5 receptors, through which HIV virus can infect white blood cells.’

The genetic risk factor is located on chromosome 3 that consists of many genes. Several genes in its vicinity encode receptors in the immune system. One of these receptors - CCR5 - is HIV to infect white blood cells.

Zeberg found that people who carried the risk factor for COVID-19 had fewer CCR5 receptors. This led him to test whether they also had a lower risk of becoming infected with HIV.

By analyzing patient data from three significant biobanks (FinnGen, UK Biobank, and Michigan Genomic Initiative), he found that carriers of the risk variant for COVID-19 had a 27 percent lower risk of contracting HIV.

"This shows how a genetic variant can be both good and bad news: Bad news if a person contracts COVID-19, good news because it offers protection against getting infected with HIV", says Zeberg.

However, since HIV only arose during the 20th century, protection against this infectious disease cannot explain why the genetic risk variant for COVID-19 became so common among humans as early as 10,000 years ago.

"Now we know that this risk variant for COVID-19 protects against HIV. But it was probably protection against yet another disease that increased its frequency after the last ice age", Zeberg concludes.



Medindia