UBC team locates weak spot in virus

Vulnerability found in major variants, including Omicron

Researchers at the University of British Columbia say they have discovered a weakness in major COVID-19 strains that could lead to universally effective treatments for those infected with most variants of the virus.

Over time, COVID has managed to mutate and stay ahead of treatments but this discovery will enable researchers to target a specific weak point found on the virus to neutralize it, they say.

“Knowing that this site exists, that it is largely unchanged across all the variants tells us where we should focus and refine antibody design so we can make a better antibody,” says Sriram Subramaniam, a professor at the UBC faculty of medicine and senior author of the study.

“The real value of the discovery is the identification of where to focus the design efforts.”

The discovery’s applications lay in treatment, he said, rather than in vaccines.

The vulnerability is found across all major variants, including the BA.1 and BA.2 Omicron subvariants.

The findings are to be published Thursday in the research journal, Nature Communications.

The UBC team is the same one that, last December, was the first in the world to get a molecular-level look of the Omicron variant using cryo-electron microscopy.

The method uses beams of electrons to visualize shapes of tissues.

At the time, the researchers found the variant’s spike protein, which viruses use to get into cells and infect them, mutated more than other variants.

Now through the same technology, in collaboration with the University of Pittsburgh, a site on the spike protein was found where antibodies can connect and neutralize the variant. The vulnerability does not mutate often, said Subramaniam.

“It’s virtually certain that we will see more mutations as time goes by,” Subramaniam said. “The goal really here is to stay ahead of the virus and identify which parts are least likely to be mutated and zero in there.”

According to Health Canada, the country had just over 25,000 COVID cases in the first week of August, the most recently available data.

The figure brings the country’s total case count to 4.1 million since the start of COVID with around 43,000 deaths.

Cases reached record levels in late 2021 and early 2022 as the highly infectious Omicron variant took hold worldwide.

Subramaniam explains antibodies are like a key fitting into a lock when the right one is used to fight a virus.

When the virus mutates, the key no longer works. Researchers have effectively been looking for a master key.

Also discussed in the findings is how the antibody fragment VH ab6 has been effective against major COVID variants. The antibody attaches to the identified weak point and prevents it from entering human cells. Subramaniam said it unlocks “a whole new realm” for treatments.

“The fact that it can bind across all these variants, that’s exciting,” he said.

Though antibodies to fight COVID have been developed, they have also weakened with the virus’s mutation over time.

But with the discovery of this weak point on COVID spike proteins, more potent antibodies can be developed, Subramaniam said.