Fig. 2
SFTSV vaccines confer complete protection against lethal SFTSV challenge in ferrets. a Immunization schedule (Supplementary Fig. 1b presents a detailed timeline of vaccination and immune analysis). b T-cell immunogenicity of SFTSV DNA vaccines in ferrets. IFN-γ ELISpot assays were performed to detect antigen-specific IFN-γ-producing T cells by stimulating peripheral blood mononuclear cells (PBMCs) from vaccinated or non-vaccinated (control) ferrets with OLP pools. Data represent the average number of spot-forming units (SFUs) per 2 × 105 PBMCs. c Neutralizing antibody response to SFTSV CB1/2014 strain (genotype B) generated by SFTSV DNA vaccines in vaccinated ferrets. The amount of neutralizing antibody against SFTSV was determined based on FRNT50. d Survival of vaccinated (n = 8, blue line) and non-vaccinated control (n = 7, red line) ferrets after lethal SFTSV challenge. e Circulating viral titers of vaccinated (blue bars, symbols, and line) and non-vaccinated (red bars, symbols and line) ferrets after SFTSV challenge. Blood was collected from ferrets every other day, and viral copy numbers were determined by real-time PCR. f Platelet counts of vaccinated (blue bars, symbols and line) and non-vaccinated (red bars, symbols, and line) ferrets after SFTSV challenge. The normal platelet count range in ferrets is 171.7–1280.6 × 103 per μL. Dashed lines indicate normal platelet count values. g, h Temperature (g) and temperature relative weight (h) of vaccinated (blue line) and non-vaccinated (red line) ferrets after SFTSV challenge. Data are presented as mean ± s.e.m. Asterisks next to the symbols on graphs indicate significance between vaccinated and control ferrets per dpi. Asterisks next to the group labels indicate significance between groups indicated. Statistical significance was determined by two-tailed Mann–Whitney U-test (b, c), log-rank (Mantel-Cox) test (d), or two-way ANOVA test with Sidak correction (e–h). *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. Source data are provided as a Source Data file
