Fig 2: Induction of cellular and humoral immune responses by PolyPEPI-SCoV-2 vaccine in mouse models. Animals received PolyPEPI-SCoV-2 or Vehicle subcutaneously at days 0, 14. IFN-γ-producing T cell responses elicited by PolyPEPI-SCoV-2 expressed as fold change in BALB/c (A) and Hu-mouse (B) models compared to the respective Vehicle cohorts; diversity of vaccine-induced T cell responses after two doses at day 28 in BALB/c (C) and Hu-mouse (D) models by ex vivo ELISpot. Test conditions: stimulation with 30-mer S-pool (three S-peptides), N-pool (four N-peptides), M-peptide, E-peptide, or 9-mer pools (s-pool, n-pool, e1, m1 peptides). For Fold change calculation the average dSFU values of the 30-mer and 9-mer stimulation conditions are pooled. (E,F) PolyPEPI-SCoV-2 induced Th1 response and no significant Th2 cytokine induction shown as average of vaccine-specific CD4+ and CD8+ T cells producing IL-2, TNF-α, IFN-γ, IL-5 or IL-10 in BALB/c (E) and Hu-mouse (F), using Intracellular cytokine staining. Mean +/-SEM are shown. 2 × 105 cells were analyzed, gated for CD45+CD3+CD4+/CD8+. Average percentage was obtained by pooling the background-subtracted values of the 30-mer stimulation conditions for each cytokine for CD4+ and CD8+ splenocytes. IgG production measured from the plasma of BALB/c (G) and Hu-mice (H). N = 6 animals at each time point, *p < 0.05, **p < 0.001 (Mann-Whitney U).