Figure 6
Changes of anti-V3 Ab-mediated neutralization in vaccine recipients in the course of immunization. Samples from 6 VAX003 and 3 VAX004 participants were tested in duplicates. (a) Neutralization mediated by anti-V3 Abs was assessed by measuring neutralization activity of plasma treated with or without V3 peptide (20 µg/mL, B.MN sequence, cyclic and nonbiotinylated) against SF162. Areas under the curve (AUC) of untreated and V3-peptide-treated plasma from early, mid-, and final time points are shown for 1 vaccinee. ∆AUC (open bar) was calculated by subtracting AUC of untreated plasma (top bar) from that of treated plasma (solid bar). (b,c) Neutralization by V3 Abs was undetectable at early time points (black), arose at mid-time points (blue), and declined after the final boost (red). ∆AUC ± standard errors are shown. **P < 0.01, ****P < 0.0001by ratio paired 2-tailed t test. (d) ∆AUC values correlated with ELISA V3-binding Ab levels detected in corresponding plasma samples. Correlation analysis was performed using the nonparametric Spearman test.
