Fig. 2.

ZIKV-3′UTR-∆10-LAV protects young A129 male mice against testis infection and injury. a Scheme of immunization of 3-week-old A129 male mice with 10⁴ FFU of ZIKV-3′UTR-∆10-LAV (∆10; n = 6) or PBS sham (n = 4 or 6). At day 28 post immunization, mice were measured for neutralization antibody titers. On the same day, mice from one sham group and mice from ∆10-immunized group were challenged with 10⁶ FFU of ZIKV-PRVABC59, and viremia was measured at day 2 post challenge (day 30 post immunization). At day 49 post immunization, mice were analyzed for sperm counts and viral load in the testis. b Viremia after immunization with ∆10 vaccine candidate. c NT₅₀ values of antibody neutralization at day 28 post immunization were measured for individual animals in each group. The dashed lines indicate the limit of detection (LOD) of the assay. d Viremia at day 2 post challenge (day 30 post immunization) with ZIKV PRVABC59. e Viral load in the testis at day 21 post challenge (day 49 post immunization). f, g Total (f) and motile (g) sperm counts at day 21 post challenge. h, i Testis weight (h) and representative images of testis (i) from animals from sham, sham with challenge, and ∆10-immunized and challenged groups at day 21 post challenge. Scale bar, 1 mm. Asterisks indicate significant differences (one-way ANOVA: ****P-value < 0.0001; ***P-value < 0.001). Nonsignificant (n.s.), P-value > 0.05. All negative samples are plotted at the half value of LOD. Error bars represent SDs