Figure 3: Dapivirine PK/PD correlation in vaginal fluid Correlation between CVL antiviral activity against HIV-1BaL infection in JTCCR5 cells and dapivirine concentrations in vaginal fluid at the end of the first ring-use period for Group A (ring worn for 28 days) and Group B (ring worn for 35 days) participants (Spearman PK/PD correlation; neat, r = 0.49 and 1:10, r = 0.77). Samples with dapivirine levels below the LLOQ were attributed the value of 0.1 ng/ml so that values could be plotted on a log scale.