FIG 3.

S. sonnei antigen-specific serum antibody titers after oral live S. sonnei vaccine candidate WRSS1 immunization. Serum IgA, IgG, and IgM antibody titers (GMT ± SE) were measured by ELISA for 13 vaccinees and 6 placebo controls on study days 0, 14, and 28. Vaccinees were subdivided into WRSS1 shedder (WS) (blue dotted line; n = 9) and WRSS1 nonshedder (WNS) (red dotted line; n = 4) groups. Responses of placebo controls (n = 6) are shown as black dotted lines. A statistical differences between WS and the placebo groups was assessed using the Mann-Whitney test: P = 0.001 for both LPS- and INV-specific IgA titers.