The Omicron variant of COVID-19 may have greater transmissibility but less aggressive symptoms than previous variants, a preliminary study suggests. Researchers from Big Data firm Nference found that Omicron contains a fragment of genetic code that is also present in HCoV-229E, a coronavirus that causes the common cold. 

This particular mutation could have originated in a person who concurrently had SARS-CoV-2  and HCoV-229E infections. According to the study authors, HCoV-229E has not been detected in other COVID-19 variants. 

Why Might This Shared Genetic Code Make Omicron More Infectious?

The fragment of the common seasonal virus HCoV-229E that Omicron shares could potentially render the variant “more accustomed to human hosts,” said biological engineer and study co-author Venky Soundararajan. This may enable Omicron to sidestep certain immune responses and transmit “more efficiently with human beings.”

Scientists have already determined that SARS-CoV-2 can infect people who are also infected with other coronaviruses. Both types of virus cells can be present in a patient’s lungs and gastrointestinal system, explained Soundararajan, which could lead to an exchange of genetic material.

Concern over Omicron’s possible increased transmissibility is supported by real-time evidence. Mutations could make it far more transmissible than variants such as Delta. The country’s National Institute for Communicable Diseases in South Africa just reported that Omicron overtook previous variants in that country in November, with infection numbers nearly quadrupling over a four-day period. 

New Variants and Silver Linings

The rapid rise in South Africa’s infection rate has not resulted in a comparable increase in hospitalizations. While that may be “comforting,” said top U.S. infectious-diseases expert Anthony Fauci in an interview, it may simply reflect the time lag often seen between infection and help-seeking. 

Still, there may be a silver lining. Viruses evolve to become more transmissible and perpetuate themselves. During this process, said Soundararajan, they tend to lose some of the traits that cause severe illness, but much more data is needed before this can be confirmed about Omicron. In the meantime, he added, it’s important to do what we can to combat viral transmission.

According to the World Health Organization, travel bans and border closings are only effective if implemented at the start of an outbreak. Vaccines, on the other hand, can help prevent the formation of more infectious variants. Equalizing the global distribution of vaccines, say experts, and overcoming vaccine hesitation–particularly in the U.S.–could go a long way toward bringing further mutations and the resulting transmissions to a halt.

*Cheng, A. (2021, Dec. 4). Omicron Possibly More Infectious Because It Shares Genetic Code with Common Cold Coronavirus, Study Says. The Washington Post.   https://www.washingtonpost.com/health/2021/12/04/omicron-coronavirus-transmissible-cold-variant/

Much about the novel coronavirus, i.e., COVID-19, is still not fully understood. As research progresses and our knowledge of the virus increases, information can change rapidly. We strive to update all of our articles as quickly as possible, but there may occasionally be some lag between scientific developments and our revisions.