Figure 1: The graph shows the HCV RNA kinetics one week after PEG-IFN + RBV treatment of chronic hepatitis C. The viral decay slope, δ, indicating the decline of HCV at week 1, is (V0 – V1)/(W1 – W0). The viral load at baseline and week 1 is V0 and V1, respectively. W1=week 1. W0=week 0. The effectiveness in blocking virion production or the rate of HCV clearance at W1, ε, is (V0 – V1)/V0.