Fig. 3.
Safety of pZIKV-3′UTR-Δ20 in male mice. (a) Experimental design. Six-week-old male A129 mice were immunized with pZIKV-3′UTR-Δ20 (1 μg), pZIKV-WT (1 μg), or DPBS (sham) via intramuscular (IM) injection and electroporation (EP) using TriGrid™. On day 29 post-immunization, mice were sacrificed for analysis. Neutralizing antibody titers were measured on day 29 post-immunization using an mCherry ZIKV neutralization assay (b). Viral loads in mouse brain (c), spleen (d), and testis (e) were determined by a focus-forming assay. The L.O.D.s for organ viral load and NT50 were 100 FFU/g tissue and 100-fold dilution, respectively. (f) Testis weight. (g) Representative images of testes from each group. The epididymis was harvested for counting total sperm (h) and motile sperm (i). Individual mice are indicated by different colors and symbols. The means and standard deviations are shown. A one-way analysis of variance (ANOVA) test was performed to determine the statistically significant differences among groups.