Study: People with immunity to original COVID-19 likely to have protection against Omicron

Editor's Note

There is a growing concern that ongoing evolution of COVID-19 could lead to variants that are capable of avoiding some or all of the immune response generated by prior infection or vaccination. To this end, Johns Hopkins researchers examined whether mutations in the Omicron variant gave it the ability to avoid recognition by immune system cells known as CD8+ T-cell or “killer T cells” in those previously infected with COVID-19.

In a previous study, the researchers found that in people infected with original COVID-19, specific epitopes (ie, portions of a protein that elicit an immune response) from the virus were recognized by the T cells, which elicited an attack on the virus. Blood samples were probed with 408 different SARS-CoV-2 epitopes, and the T cells in the samples recognized 52.

For this analysis, the researches examined the 52 epitopes to determine if they had been altered by mutations that would enable the virus to avoid recognition and attack by T cells.

They found that Omicron’s mutational differences from the original COVID-19 strain did not give it the ability to avoid killer T cell recognition, and, therefore, a previously infected person’s immune response to Omicron should be as strong as it was to original COVID-19. The same most likely applies to vaccinated individuals, the researchers note.