Immune System T-Cells Can Fight Off Omicron

WEDNESDAY, Jan. 5, 2022 (HealthDay News) -- While the Omicron variant appears wily enough to evade people's antibodies, researchers report that it should have a much harder time slipping past a person's T-cells.

"Despite being a preliminary study, we believe this is positive news. Even if Omicron, or some other variant for that matter, can potentially escape antibodies, a robust T-cell response can still be expected to offer protection and help to prevent significant illness," said study co-leader Matthew McKay, from the University of Melbourne in Australia.

The virus’ spike protein enables it to attach and enter human cells. Current vaccines trigger neutralizing antibodies to try and block this, but preliminary research suggests this is less effective against Omicron, which has developed a multitude of spike protein mutations.

The researchers analyzed more than 1,500 fragments of SARS-CoV-2’s viral proteins called epitopes, which have been found to be recognized by T-cells in recovered COVID-19 patients or after vaccination.

They found that only 20% of the virus epitopes from the spike showed mutations associated with Omicron. Even so, this small number of mutations doesn’t mean the virus can evade the body’s T-cells, the researchers noted.

"Among these T-cell epitopes that have Omicron mutations, our further analysis revealed that more than half are predicted to still be visible to T-cells," said study co-leader Ahmed Abdul Quadeer, a research assistant professor at Hong Kong University of Science and Technology's (HKUST) Department of Electronic and Computer Engineering.

"This further diminishes the chance that Omicron may escape T-cells' defenses," Quadeer said in an HKUST news release.

The news was also positive when the research team analyzed other virus proteins. They found that more than 97% of non-spike T-cell epitopes did not have mutations associated with Omicron.

"These results overall, would suggest that broad escape from T-cells is very unlikely," McKay said. "Based on our data, we anticipate that T-cell responses elicited by vaccines and boosters, for example, will continue to help protect against Omicron, as observed for other variants."

The findings, published Jan. 2 in the journal Viruses, add to a growing body of evidence that suggests Omicron is unlikely to be able to evade T-cells.

More information

The U.S. Centers for Disease Control and Prevention has more information on COVID-19.

SOURCE: Hong Kong University of Science and Technology, news release, Jan. 3, 2022