The Omicron variant of the virus that causes COVID-19 likely acquired at least one of its mutations by picking up a snippet of genetic material from another virus – possibly one that causes the common cold.
Researchers say that this particular genetic sequence does not appear in any earlier versions of the coronavirus, called SARS-CoV-2, but is seen in many other viruses including those that cause the common cold.
By inserting this particular snippet into itself, Omicron might be making itself look “more human,” which would help it evade attack by the human immune system, said Venky Soundararajan of Cambridge, Massachusetts-based data analytics firm nference, who led the study.
The study, “Omicron variant of SARS-CoV-2 harbors a unique insertion mutation of putative viral or human genomic origin,” was published December 2, 2021, on OSFPreprints.
Should this prove to be true, it could mean the virus transmits more easily, while only causing mild or asymptomatic disease, CTV News Canada is reporting.
At this point in time, there is much that scientists do not know about the Omicron variant, like does it cause more serious disease, or is it more infectious? It is going to take several weeks to get answers to these and other questions.
A look into the study
Cells in the lungs and in the gastrointestinal system can harbor both SARS-CoV-2 and common-cold coronaviruses simultaneously, based on earlier studies. This in itself, can set up the scene for viral recombination.
This is a process in which two different viruses in the same host cell interact while making copies of themselves, generating new copies that have some genetic material from both “parents.”
This new mutation could have first occurred in a person infected with both pathogens when a version of SARS-CoV-2 picked up the genetic sequence from the other virus, Soundararajan and colleagues said in the study, which has not yet been peer-reviewed.
This genetic sequence appears quite often in the coronaviruses that cause colds in people – known as HCoV-229E – and in the human immunodeficiency virus (HIV) that causes AIDS.
South Africa, where Omicron was first identified, has the world’s highest rate of HIV, which weakens the immune system and increases a person’s vulnerability to infections with common-cold viruses and other pathogens.
It is quite possible that in that part of the world, there could have been many cases of recombination that added this ubiquitous set of genes to Omicron, Soundararajan said.
“We probably missed many generations of recombinations that occurred over time and that led to the emergence of Omicron,” Soundararajan added.
Soundararajan also adds that it is all the more important that people are getting the currently available COVID-19 vaccines.
“You have to vaccinate to reduce the odds that other people, who are immunocompromised, will encounter the SARS-CoV-2 virus,” Soundararajan said.