Anti-Tat humoral immune response in vaccinees. (A) Percentage of subjects producing Anti-Tat Abs (responders) after Tat immunization (7.5 μg, 3x n = 40; 7.5 μg, 5x n = 40; 30 μg, 3x n = 38; 30 μg, 5x n = 37). (B) Kaplan-Meier estimates showing the cumulative probability of anti-Tat Ab durability in responders stratified according to treatment groups and up to week 144 of follow-up (n = 123, median follow-up of 96 weeks). (C) Percentage of subjects in each treatment group producing anti-Tat IgM (light blue), IgG (red), or IgA (white) Abs. (D) Percentage of subjects in each treatment group producing two (IgM and IgG, in blue) or three (IgM, IgG and IgA, in red) anti-Tat Ab classes. (E) Anti-Tat IgM (light blue) and IgA (white) peak titers between 4 and 24 weeks since the first immunization in subjects positive for IgM (7.5 μg, 3x n = 16; 7.5 μg, 5x n = 20; 30 μg, 3x n = 24; 30 μg, 5x n = 23) or IgA anti-Tat Abs (7.5 μg, 3x n = 7; 7.5 μg, 5x n = 9; 30 μg, 3x n = 19; 30 μg, 5x n = 22). (F) Anti-Tat IgG Ab peak titers between 4 and 24 weeks since the first immunization in subjects positive for IgG anti-Tat Abs (7.5 μg, 3x n = 24; 7.5 μg, 5x n = 24; 30 μg, 3x n = 32; 30 μg, 5x n = 31). Box plots represent the median, 25th and 75th percentile, with the minimum and maximum values; the outliers are not represented in the graphs.