- The Omicron variant circulates exclusively in metropolitan France: since September, it represents 100% of the sequences analyzed, according to Public Health France.
- Within the Omicron variant, the BA.5 sub-lineage is now the majority: it represents 91% of the sequences.
- Nearly 57,000 new cases of Covid-19 were confirmed on October 20. The epidemic has been gaining ground in France since the end of August.
Covid-19 is most likely a zoonosis, a disease transmitted to humans from animals. But it turns out that the new variants could also come from it, especially the Omicron variant.
In a new study published in Proceedings of the National Academy of Sciences, the official journal of the American Academy of Sciences, researchers from the University of Minnesota School of Medicine and College of Biological Sciences have provided new insights into the origins of the Omicron variant. Their findings proved that the Omicron variant may have been transmitted from animal species to humans.
Omicron variant: there is an abnormality in the virus infection process
Why ? Because the researchers noticed a strangeness during one of the essential stages of infection by the Omicron variant of Sars-CoV-2, the virus which causes Covid-19. Infection occurs when certain proteins on the tip of the coronavirus bind and adapt to the host receptor (a cell from an infected individual, for example).
Through analysis of the structure of the virus, the researchers identified several mutations in these Omicron variant proteins that were uniquely suited to the mouse receptor and incompatible with the human receptor. This suggests that the Omicron variant may not have come directly from humans, and instead was passed to them from an animal.
Animal-to-human transmission of coronavirus threatens global health
“These Omicron mutations are evolutionary traces left by the virus during its transmission from one animal species to another”said lead author Fang Li, a Minnesota Medical School professor and director of the Center for Coronavirus Research, in a statement.
Researchers say Covid-19 is capable of infecting many animal species, which is one of the main reasons why variants keep popping up. They also point out that epidemic surveillance of rodents may be important in preventing the emergence of new variants of Covid-19 or other coronaviruses in the future. “The transmission of coronaviruses from animals to humans risks threatening global health”alerts Dr. Fang Li.