Extended Data Figure 8. mRNA-1273 elicits Th1-skewed responses compared to S-2P protein adjuvanted with alum.

BALB/c mice (n=6/group) were immunized at weeks 0 and 2 weeks with 1 (red) or 10 μg (purple) of mRNA-1273 or 10 μg of SARS-CoV-2 S-2P protein adjuvanted with alum hydrogel (orange). Control mice were administered PBS (gray) (n=3). (a-b) Sera were collected 2 weeks post-boost and assessed by ELISA for SARS-CoV-2 S-specific IgG1 and IgG2a. Endpoint titers (a) and endpoint titer ratios of IgG2a to IgG1 (b) were calculated. (c-d) Splenocytes were collected 4 weeks post-boost to evaluate IFN-γ, IL-4, IL-5, and IL-13 cytokine levels secreted by T cells re-stimulated with S1 (c) and S2 (d) peptide pools, measured by Luminex. (b) Immunogens were compared by two-sided Mann-Whitney test. (c-d) For cytokines, all comparisons were compared to PBS control mice by Kruskal-Wallis ANOVA with Dunn’s multiple comparisons test. * = p-value < 0.05, ** = p-value < 0.01, *** = p-value < 0.001, **** = p-value < 0.0001. Data are presented as GMT +/− geometric SD (a) or mean +/− SD (b-d). Dotted line represents assay limit of detection.