borderline significantp=0·0498
When comparing the results between the younger and older adults who received the same vaccine, there were no significant differences in the number of omicron-reactive IFNγ + CD4 + and IFNγ + CD8 + T cells in response to the spike or S/M/N/E peptide pool, except for in younger adults who received CoronaVac, who showed a higher number of CD4 + IFNγ + T cells using S/M/N/E peptide pool for stimulation, which was borderline significant (p=0·0498; appendix p 17 ).