A group from National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA, etc. has reported on effects of SARS-CoV-2 Omicron variant onto existing SARS-CoV-2 CD8+ T-cell recognition.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8669839/
This study examined if the previously identified SARS-CoV-2 viral epitopes targeted by CD8+ T-cells in 52 individuals are mutated in the newly described Omicron VOC (n=50 mutations), because it is critical to determine the extent that Omicron may or may not be susceptible to existing humoral responses.
T-cell associated immunity is in general significantly more difficult for viruses to overcome due to the broad and adaptable response generated in a given individual, as well as the variety of HLA haplotypes between individuals.
It was found that of the mutations associated with the Omicron variant (n=50), only one in the Spike protein (T95I) overlapped with a CD8+ T-cell epitope (GVYFASTEK) identified in this subject population.
Despite the substantial number of mutations in the Omicron, in this population only one low-prevalence CD8+ T-cell epitope from the Spike protein contained a single amino acid change. No other mutations were associated with our previously identified SARS-CoV-2 T-cell epitopes. These data suggest that virtually all individuals with existing anti-SARS-CoV-2 CD8+ T-cell responses should recognize the Omicron variant, and that SARS-CoV-2 has not evolved extensive T-cell escape mutations at this point.