FIG 4.

Combination treatment regimens enhance the antiviral effect of K22 on ZIKV. Vero B4 cells were infected with ZIKV (MOI = 0.1 TCID₅₀/cell) for 1 h, before the inoculum was discarded and the cells were washed with PBS. The compounds were added at various concentrations. (a) K22 single treatment; (B) RBV single treatment; (c) IFN-α single treatment; (d) K22-RBV combination treatment; (e) K22–IFN-α combination treatment; (f) RBV–IFN-α combination treatment. The cell culture supernatants were collected at 24 h p.i., and viral titers were determined as the number of TCID₅₀ per milliliter. The results represent the mean + SD (n = 3). The dashed lines indicate the limit of detection. P values were determined by 1-way ANOVA followed by Dunnett's multiple-comparison test. ****, P ≤ 0.0001; ***, P ≤ 0.001; **, P ≤ 0.01; n.s., not significant. (g to i) Three-dimensional blots depicting the viral titers for each combination.