In the low- and high-dose vaccine groups (dpi 7, days post-infection 7), IFN-γ signals were significantly higher when immune splenocytes were stimulated with a spike peptide cocktail (p <0.01) whereas the IFN-γ signal did not significantly increase when splenocytes were stimulated with either RBD or N peptides compared with medium (Figure 4). Here, IFNG is linked to infection.