Neutralization activity. (A) Longitudinal analysis of autologous neutralization activity (NA) against patient isolates derived at the beginning of the first and the fifth cycle. Reciprocal titers achieving a 70% neutralizing activity are depicted. Squares indicate first-cycle isolate (n = 10); circles, fifth-cycle isolate (n = 22). Gray shaded symbols indicate plasma from cycle 1 (week 2), cycle 2 (week 12), cycle 3 (week 22), and cycle 4 (week 32). Open symbols depict plasma samples from cycle 5 (week 48). Titers at individual time points were compared using 1-way ANOVA (Kruskal-Wallis test with the Dunn multiple comparison post test). (B) Seventy percent neutralizing titers of sera from cycles 1 (week 2, gray), 4 (week 32, black), and 5 (week 48, open symbol) against first-(squares) and fifth-cycle isolates (circles) were compared using the Wilcoxon signed rank test. (C) Autologous neutralization activity at baseline (week 2) against fifth-cycle isolates from patients who potently control viremia (open symbol) or who do not control viremia (gray) were compared using the unpaired t test. (D) Mean increases in 70% neutralizing activity over baseline (week 2) activity in cycles 1 to 4 and cycle 5 against fifth-cycle isolates in controlling (open symbol) and noncontrolling (gray) patients were compared using the unpaired t test. (B-D) All significant observations were significant on the individual level and also after Bonferroni correction.