Figure 4.

Single-dose immunization of C7a/t protects A129 mouse from ZIKV infection. (a) Experimental design. Three groups (n=5) of three-week-old A129 mice were subcutaneously injected with C7a/t virus, WT ZIKV, or DPBS (sham). Viremia was monitored from days 2 to 4 post-infection. Following immunization, mice were monitored for weight loss over 12 days. On days 28 and 42 post-immunization, mice were bled and quantified for pre- and post-challenge neutralizing antibody titers (NT₅₀). Mice were subcutaneously challenged with 10⁶ PFU of ZIKV PRVABC59 strain on day 28 post-immunization. On days 2 and 3 post-challenge (equivalent to days 30 and 31 post-immunization), mice were bled to measure viremia post-challenge. (b) Mouse weight post-immunization. Two-way ANOVA was used to determine the statistical significance in weight change among groups. (c) Viremia post-immunization. Viremia was determined by focus-forming assay on BHK-HA-C cells. Limit of detection (L.O.D.), 100 PFU/ml. (d) Survival after immunization. (e) Pre-and post-challenge neutralizing antibodies. NT₅₀s were determined by ZIKV/mCherry neutralization assay (see details in Methods). L.O.D., 100 reciprocal sera dilution. (f) Viremia post-challenge. Viremia on days 2 and 3 post-challenge were measured by plaque assay. An unpaired nonparametric Mann-Whitney test was used for analyzing the statistical significance of viremia and NT₅₀s.