FIG 2.

Extinction of high-fitness hepatitis C virus by combinations of favipiravir and ribavirin. (A, B) Viral titers obtained after a single infection of HCV p0, HCV p100, or HCV p200 (the virus is indicated at the top) in the absence or presence of the drug concentrations given on the abscissae (Mock, mock infected; RIB, ribavirin; FPV, favipiravir). In each panel, +RIB and +FPV mean that the concentrations used in the combination were the same concentrations of the drugs used individually. Titrations were carried out in triplicate, and the statistical significance of the differences was determined by ANOVA. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, not significant. (C) The response of HCV p0, HCV p100, and HCV p200 subjected to 10 serial infections in the absence or the presence of the drug concentrations indicated in the key. The statistical significance of the differences was determined by two-way ANOVA. ***, P < 0.001; ns, not significant. The origins of the viruses and further experimental details are described in Materials and Methods.