A new study, published in the Proceedings of the National Academy of Sciences, shows that a gene variant that protects against more severe covid-19 is inherited by Neanderthals.

Those who carry this gene variant are 20 percent less likely to be admitted to intensive care, according to a large international study published in Nature in December.

The gene variant is becoming more common

The new study shows that the protective gene variant is found in almost half of all people outside Africa.

The gene variant is said to have been transmitted from Neanderthals to humans by mating about 60,000 years ago.

During the last millennium, however, the occurrence of the gene variant has for some reason increased in frequency.

- We do not understand why it has become so common.

This variant protects not only against covid-19 but also against infections with other viruses such as hepatitis C, Sars-CoV-1 and the West Nile virus.

At some point in history, we have needed this gene variant, says Hugo Zeberg, a researcher at Karolinska Institutet.

By mapping the origin of the gene variant, one can increase the understanding of why some people become more ill than others and how it can differ between regions and continents.

Can be used for risk assessment of covid disease

The same research couple made a discovery last autumn that another gene variant, which increases the risk of becoming seriously ill in covid-19, is also inherited from Neanderthals.

It is also worn by people outside Africa.

Today, no tests are performed on which gene sets a patient carries when being cared for covid-19.

But in the future, the knowledge could be used to make a risk assessment of the patient, both if it carries the protective gene variant or the one that increases the risk.

- It would be rational to look at this risk variant in patients because, just like old age, it contributes to an increased risk of becoming seriously ill, says Svante Pääbo, professor of genetics at the Max Planck Institute for Evolutionary Anthropology.