Fig. 4: Single-dose vaccination protects Ifnar1^−/− mice against CCHFV infection.

A Study design. Ifnar1^−/− mice (n = 12 per vaccination group) received a single subcutaneous immunization. Five weeks later, the mice intraperitoneally challenged with 3000 TCID₅₀ of CCHFV. Six mice per group were monitored for survival and body weight over 14 days, and the remaining six were euthanized at 5 dpi to assess viral loads. B Vaccine design. Single-dose vaccination regimen detailing antigen composition, and administration route. C CCHFV-specific IgG responses. NP-specific IgG levels in Ifnar1^−/− mice were measured by ELISA five weeks post-immunization. D Survival analysis. Statistical significance was determined using a Log-rank (Mantel-Cox) test. E Body weight changes. F Viremia. Viral RNA loads in blood were quantified by qRT-PCR at 5 and 14 dpi. G, H. Tissue viral loads in the liver (G) and spleen (H) at 5 and 14 dpi. Data are presented as the mean ± SEM. The dashed line indicates the limit of detection. Statistical significance for (F-H) was determined by Kruskal–Wallis test followed by Dunn’s multiple comparisons test. Exact p values are shown.