Figure 4.

Transfer of JEV-immune mouse sera increases the survival of JEV-infected mice but decreases that of ZIKV-infected mice. (A–J) 1-d-old naive C57BL/6 mice were injected s.c. with the indicated volumes of mock- or JEV-immune mouse sera, and 6 h later, the mice were injected s.c. with (A–F) ZIKV (10² FFU) or (G–J) JEV (12 PFU). Mouse weights and survival were recorded daily for up to 28 d. Data are presented as the mean ± SD and are pooled from two experiments, each with five to eight mice per group (A–F) or two or three mice per group (G–J). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 by two-tailed Mann–Whitney U test (A, C, E, G, and I) or log-rank test (B, D, F, H, and J).