Canadian Study Discovers Why Omicron Transmits So Rapidly

Students walk past the UBC sign at the University of British Columbia in Vancouver, in a file photo. Darryl Dyck/The Canadian Press

The University of British Columbia announced Wednesday that it has completed the world’s first molecular-level analysis of Omicron, revealing possible reasons behind the new COVID-19 variant’s high transmissibility.

With the help of a “near atomic resolution” cryo-electron microscope, UBC’s analysis revealed that Omicron’s heavy mutations and ability to evade immunity contribute to its high transmissibility, according to Dr. Sriram Subramaniam, one of the researchers.

“Both the characteristics we see as a result of spike protein mutations—strong binding with human cells and increased antibody evasion—are likely contributing factors to the increased transmissibility of the Omicron variant,” said Subramaniam, a professor in the university’s faculty of medicine’s department of biochemistry and molecular biology, in an article on UBC News.

“These are the underlying mechanisms fuelling the variant’s rapid spread and why Omicron could become the dominant variant of SARS-CoV-2 very quickly.”

The Omicron variant has a record 37 spike protein mutations, which is roughly three to five times more than any previously identified COVID-19 variants.

“This is important for two reasons. Firstly, because the spike protein is how the virus attaches to and infects human cells. Secondly, because antibodies attach to the spike protein in order to neutralize the virus,” Subramaniam said

“Therefore, small mutations on the spike protein have potentially big implications for how the virus is transmitted, how our body fights it off, and the effectiveness of treatments.”

Usually when a virus mutates, it could potentially become weaker and less transmissible, but that was not the case for the Omicron variant, Subramaniam said in an interview with the Toronto Star.

“So when you have such a large number of mutations, the remarkable thing about this particular variant is it still retains about the same level of efficiency at recognizing our cells [as previous variants].”

He also noted that the Omicron spike protein is more adept than that on any other variant at evading the antibodies used as treatments, as well as dodging the immunity produced by either vaccines or natural infection.

Having taken a closer look at Omicron, Subramaniam said the surprising thing about the virus is that while its interface looks different, it remains effective at binding itself to human cells.

“The good news is that knowing the molecular structure of the spike protein will allow us to develop more effective treatments against Omicron and related variants in the future,” he said in the UBC article.

“Understanding how the virus attaches to and infects human cells means we can develop treatments that disrupt that process and neutralize the virus.”