Figure 7.

In vivo rescue and safety of an attenuated rZIKV (rZIKVatt). Four-to-five-week-old IFNAR−/− A129 male (N = 3) and female (N = 3) mice were inoculated with 100 µg/mouse (top panels) of the pBAC cDNA clone of an attenuated rZIKV (pBAC-ZIKVatt) or with 100 µg/mouse of empty pBAC plasmid (middle panels) both complexed to LPF. As internal control, mice were infected SC in the footpad with a sublethal dose (0.1 X MLD₅₀) of the in vitro generated rZIKVatt (bottom panels). Body weight (A), and survival (B) were evaluated at the indicated dpi (top and middle panels) or post-infection with rZIKVatt (bottom panels). Error bars represent SD of the mean for each group of mice. Mice were bled at 3, 6 and 9 dpi or post-infection with rZIKVatt and viral titers in sera were determined by immunofocus assay (FFU/ml) (C). Symbols represent data from individual mice and bars the geometric means of viral titers. &, virus not detected in two mice; ND, not detected. Dotted black lines indicate the LoD (200 FFU/ml). No statistically significant differences in survival were observed in mice inoculated with pBAC-ZIKVatt, empty pBAC, or rZIKVatt, using a Long-rank test. Statistically significant differences (p = 0.034) in viral titers were observed in mice inoculated with pBAC-ZIKVatt or rZIKVatt using ANOVA test.