FIG 3.

Passive transfer of serum from vaccinated mice protects against lethal challenge. (A to C) Groups of 4 to 5 male and female B6.129-Stat2^−/− mice were injected intraperitoneally with 200 μl of pooled serum before a challenge with 10 LD₅₀s (158 PFU per mouse) of MR766 ZIKV intradermally. (D to F) Groups of 4 male and female B6.129-Stat2^−/− mice were injected intraperitoneally with 200 μl of pooled serum before a challenge with 1,000 PFU of PRVABC59 ZIKV intradermally. Weight loss was monitored daily. Clinical scoring was conducted using the predefined criteria, with a maximum possible score of 7: impact on walking (1), unresponsiveness (1), left hind leg paralyzed (1), right hind leg paralyzed (1), left front leg paralyzed (1), and right front leg paralyzed (1). Deceased animals were awarded a score of 7. The ratios in the figures indicate the number of animals that survived challenge over the total number of animals per group. The Mantel-Cox and Gehan-Breslow-Wilcoxon tests were used to analyze statistical significance of survival between two groups. A multiple t test and the Holm-Šidák method were used to determine statistical significance at each time point for the weight curve and the clinical score. Asterisks indicate statistical significance of a group (*, P < 0.05) in a comparison with mice vaccinated with BSA.