Fig. 3: Antigen specific humoral and T helper cell response in BA.5 infected mice.

Assessment of immunogencity of BA.5 infection against wild type RBD protein or spike protein was done by evaluating the cellular T cell effector response. Splenocytes from the infected mice at day 6 post infection were harvested and in-vitro stimulated with (a, c, e, g, i) WT-RBD protein and (b, d, f, h, j) spike protein then assessed for (a–d) CD4⁺ T cell activation and Th1 response as well as (e–h) CD8⁺ T cell response. Dot plot and bar graph showing % frequency of (a, b) IL-2 or (c, d) IFN-γ-producing CD4⁺ T cells and (e, f) IL-2 or (g, h) IFN-γ-producing CD4⁺ T cells. Humoral response was evaluated through ELISA for (i) anti-RBD IgG antibody titer and (j) anti-Spike protein IgG antibody titer for 3 time points post infection viz day 7, day 14 and day 21 post infection. For all experiment n = 5. One way-Anova using non-parametric Kruskal–Wallis test for multiple comparison. ns non-significant, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.