Fig. 1: Characterization of immunogenicity of mRNA vaccines in mice.

A Experimental scheme. C57BL/6 J and Ifnar1^−/− mice received a prime dose followed by a booster three weeks later. Blood and spleens were collected at different time points to assess humoral and cellular immune responses. B Study design. A two-dose regimen specifying antigen composition, dosage, and administration route. C, D CCHFV-specific IgG responses. NP-specific (C) and Gc-specific (D) IgG levels in C57BL/6 J mice were quantified by ELISA. E, F Pseudovirus neutralization. Serum collected two weeks post-boost from C57BL/6 J (E) and Ifnar1^−/− (F) mice was tested for neutralization against pseudotyped CCHFV (*GPC-VSVΔG/GFP). Neutralization efficacy was determined by quantifying GFP-expressing cells, and IC₅₀ values were calculated from serum dilution curves and presented on a logarithmic scale. G, H Live virus neutralization. Serum from C57BL/6 J (G) and Ifnar1^−/− (H) mice was tested for neutralization against live CCHFV YL16070 in Vero E6 cells. IC₅₀ values were calculated from serum dilution curves based on viral inhibition, expressed on a logarithmic scale. I–K T-cell responses. IFN-γ-secreting splenocytes in C57BL/6 J mice immunized with mRNA-NP (I), mRNA-GPC (J), or mRNA-NP + mRNA-GPC (K) were quantified by ELISpot. Data represent cumulative spot-forming cells (SFCs) against the NP (I), GPC (J), and NP + GPC (K) peptide pools after background subtraction (DMSO-only controls), normalized to 10⁶ splenocytes. Data are shown as mean ± SEM. Statistical significance for (I) was determined by one-way ANOVA with Tukey’s multiple comparisons test. Statistical significance for (E–H, J, and K) was determined by Kruskal–Wallis test followed by Dunn’s multiple comparisons test. Exact p values are shown.