Discovery of 'weak spot' in COVID-19 variants could lead to better treatment options

A discovery by a team of B.C. researchers may lead to improved COVID-19 treatment options that are effective against several variants of the disease.

Researchers at the University of British Columbia say they've found a "weak spot" in COVID-19 variants, including in the latest Omicron subvariants. Their findings were published in Nature Communications on Thursday.

"This is a highly adaptable virus that has evolved to evade most existing antibody treatments, as well as much of the immunity conferred by vaccines and natural infection," said Dr. Sriram Subramaniam, a professor at UBC's faculty of medicine and the study's senior author, in a news release.

"This study reveals a weak spot that is largely unchanged across variants and can be neutralized by an antibody fragment. It sets the stage for the design of pan-variant treatments that could potentially help a lot of vulnerable people."

The researchers, who worked with a team from the University of Pittsburgh, explained that while antibody treatments have been available for COVID-19, some are less effective against muted variants like Omicron.

"Antibodies attach to a virus in a very specific manner, like a key going into a lock. But when the virus mutates, the key no longer fits," Subramaniam explained.

"We've been looking for master keys — antibodies that continue to neutralize the virus even after extensive mutations."

Researchers believe they've identified a "master key" antibody fragment that's effective against COVID-19's Alpha, Beta, Gamma, Delta, Kappa, Epsilon and Omicron variants. It can attach itself to part of the virus' spike protein, blocking it from entering human cells.

By identifying a weak spot, researchers say drug makers can use the information to create new treatments that could even be effective against future variants.

"We now have a very clear picture of this vulnerable spot on the virus. We know every interaction the spike protein makes with the antibody at this site. We can work backwards from this, using intelligent design, to develop a slew of antibody treatments," Subramaniam said.

"Having broadly effective, variant-resistant treatments would be a game changer in the ongoing fight against COVID-19."