Figure 2.

vIND-ZIKV replicates only in the presence of DOX and is attenuated compared to vIND in vitro and in vivo. (a) BS-C-1 cells were infected with wild-type strain Western Reserve (WR), vIND or vIND-ZIKV (D4W) at an MOI of 5 in the absence or presence of 1 µg/ml DOX. At 0 or 24 h, cells were collected and lysates were titered in duplicate on BS-C-1 cells in the presence of 1 µg/ml DOX. Plaques were counted 2 days post-infection and mean titers of triplicate samples are shown. (b,c) CB6F₁ mice (n = 5) were inoculated intranasally with 2 × 10⁴ PFU vIND or vIND-ZIKV (D4W) in either the absence (b) or presence (c) of 0.125 mg/ml DOX in the drinking water and were weighed daily for 21 days. Asterisks represent statistical significance (*p < 0.05, ^†p < 0.001) by two-way ANOVA (a) or two-way repeated measures ANOVA (b,c). Error bars represent SD.