FIG 7.

Functional and antigen-specific antibodies induced after S. flexneri 2a challenge. SBA (A), OPKA (B), and IpaB (C)- and VirG (D)-specific IgG titers before and 28 days after challenge in groups with different disease indexes. Data represent individual titers from all challenged individuals (n = 28), with the mean ± SEM indicated. Asterisks indicate statistically significant differences as determined by the Mann-Whitney U test (P ≤ 0.05). The numbers below the DIs at the top of each graph represent the number of subjects that seroconverted (≥2-fold SBA and OPKA titers and ≥4-fold IpaB- and VirG-specific IgG titers) over the total number of subjects, with the percent seroconversion shown in brackets.