A group of University of B.C. scientists have unveiled a molecular-level analysis of the Omicron variant that is swiftly becoming the dominant strain of COVID-19.
The analysis, which was done at “near atomic resolution” using a cryo-electron microscope, showed how the heavily mutated variant infects cells and is “highly evasive of immunity.”
Sriram Subramaniam, a professor at UBC’s faculty of medicine’s department of biochemistry and molecular biology, said that the Omicron variant had 37 spike protein mutations, much more than any previous variants.
According to Subramaniam, that has big implications for how the variant will act, because the spike protein is responsible for both how the virus attaches to and infects human cells and because its also where the antibodies attach to fight off the virus.
“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,” Subramaniam said.
The UBC analysis showed that some of the mutations increased binding affinity, or how strongly the virus attaches to human cells, while other mutations appear to decrease the strength of this bond.
“Overall, the findings show that Omicron has greater binding affinity than the original SARS-CoV-2 virus, with levels more comparable to what we see with the Delta variant,” Subramaniam said. “It is remarkable that the Omicron variant evolved to retain its ability to bind with human cells efficiently despite such extensive mutations.”
Subramaniam said that his team’s analysis confirmed what’s playing out in real life: the Omicron spike protein is “far better” than other variants at evading both the monoclonal antibodies used as COVID treatments and the immunity built with vaccines or natural infection.
“Notably, Omicron was less evasive of the immunity created by vaccines, compared to immunity stemming from natural infection in unvaccinated COVID-19 patients,” he said. “This suggests that vaccination remains our best defence against the Omicron variant.”