In keeping with the IFN-γ ELISpot responses, spike-specific CD8+ T cells increased in magnitude following omicron infection in SARS-CoV-2 naive (p = 0.02), but not previously-infected individuals, whereas non-spike populations increased significantly in both groups (p = 0.002 and p = 0.001; Fig. 6a, b), although in some cases these increases were relatively small. This evidence concerns the gene IFNG and infection.