A new study outlines how experiencing low or no symptoms from COVID-19 may be linked to a specific genetic factor inherited from Neanderthal ancestors.
The study, carried out by researchers at Germany's Max Planck Institute for Evolutionary Biology in Leipzig, and at the Karolinska Institutet in Sweden, explained how the genetic mutation reduced the risk of severe COVID-19 symptoms by approximately 20 percent, and that half of the people living outside of Africa carry this Neanderthal gene.
The study was published in the journal PNAS.
The Neanderthal gene variant both increases and decreases risk of severe COVID-19 infections
In an interesting turn, last year the same researchers showed that a major genetic factor for developing severe COVID-19 symptoms came from Neanderthals — the study was published in the journal Nature.
Now, the team builds on its previous research and explains how having certain Neantherthal genes can also act as a protective barrier.
We've heard for some time now that some people react strongly, mildly, or not at all after contracting COVID-19. Certain risk factors such as age and diabetes play a major role in these reactions, but so do gene variants.
These genes, located on chromosome 12, code for enzymes that play an important role when helping cells kill genomes of invading viruses, such as the coronavirus. The study suggests that enzymes produced thanks to the Neanderthal variant of these genes work better at protecting against severe COVID-19.
This variant was passed down to present-day humans thanks to interbreeding between Neanderthals and modern humans some 60,000 years ago. It's believed about half of the population outside of Africa has this gene variant.
"It's quite amazing that despite Neanderthals becoming extinct around 40,000 years ago, their immune system still influences us in both positive and negative ways today," said Professor Svante Pääbo from the Karolinska Institutet.
The team's new findings could help explain why certain people suffer more severely from COVID-19 and others don't.