FIG 6.

Protective efficacy of one-shot immunization with WNV-ΔNS1 in C57BL/6 mice. (A) Animal experimental schedule. (B and C) Antibody titer measurements. Four-week-old C57BL/6 female mice (n = 5 for each group) were i.p. immunized once with different dosages of WNV-ΔNS1 (3 × 10⁶ IU, 1.2 × 10⁷ IU, or 4.8 × 10⁷ IU), and sera were collected on day 14 and day 28 for IgG antibody (B) and neutralizing antibody (C) titer measurements. ND, not detected. (D to G) Analyses of morbidity, survival, and virus and antibody levels. All mice were i.p. injected with 3 × 10⁷ PFU of WT WNV at 30 days postimmunization and monitored for weight loss (D), survival (E), viremia (F), and postchallenge IgG antibody titers (G). The dashed lines in panels B, C, and F represent the limit of detection. Data represent the mean ± standard deviation of 5 mice at each time point in each group. The asterisks denote statistical differences between the indicated groups. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.