A study advances the possibility that the omicron variant, of covid-19, may have acquired a fragment of viral genetic material from another influenza causing common cold, in one of its 30,000 or so mutations.

The researchers say that this gene sequence does not appear in any previous version of the coronavirus, but is ubiquitous in many other viruses, including those that cause the common cold, and also in the human genome.

According to Venky Soundararajan of the Cambridge data analysis company by capturing this particular genetic material, the omicron may be making itself look "more human," which would help it escape attack by the human immune system.

Previous studies have revealed that cells in the lungs and gastro-intestinal system can simultaneously harbor SARS-CoV-2 and viruses from a common flu. Such co-infection sets the stage for viral recombination, 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 may help explain the easy transmissibility of the omicron variant, while causing only mild or asymptomatic disease. And despite this, scientists still don't know whether omicron is more infectious than other variants, whether it causes more serious disease, or whether it will overtake Delta as the most prevalent variant.