Fig. 6: Active immunization of mice with SUB restricts viral transmission.
A Schematic representation of the study design. KM mice were injected with recombinant SUB or PBS as a control and boosted three times at 2-week intervals. Two weeks after the last immunization, infected females were added to the feeding chamber along with one uninfected male. After 2 days, ten uninfected nymphs were added to the feeding chamber. B Antibody responses of immunized mice (n = 8 per group) measured using indirect ELISA. Each point represents the average OD450 nm in each group. The relative levels of SFTSV RNA in engorged nymphs (n = 40 for engorged nymphs fed on SUB-immunized mouse; n = 43 for engorged nymphs fed on the control mouse) (C) and skin (n = 7 for the control group (One sample was excluded because the GAPDH transcript could not be detected by qPCR); n = 8 for the SUB-immunized group) (D) bitten by infected females. Data are shown as mean ± SEM of two independent experiments. Statistical significance was determined using Student’s t-tests for the data at 14 days, 42 days and 56 days in (B) and Mann–Whitney tests for the others. **p < 0.01 and ***p < 0.005; n.s. not significant.
