Figure 2.

(A) Mucosal immune responses in Bangladeshi children and infants given 2 biweekly doses of ETVAX ± double-mutant heat-labile toxin (dmLT) against colonization factors (CFs) and LTB: (B cohorts) antibody in lymphocyte secretion (ALS) IgA response in children 24–59 months and (C cohorts) 12–23 months; (D cohorts) fecal secretory IgA (SIgA)/total SIgA response in infants 6–11 months and (table) responder frequencies (RFs) in ALS IgA and/or fecal SIgA/total SIgA in the infants. Immune responses were determined as ≥2-fold rises in ALS titers or SIgA/total SIgA levels between pre- and postimmunization specimens collected on day 7 after the first day and 5 days (day 19) after the second dose. Fold-rise responses, determined as the maximal response after the first or second dose, are shown as geometric mean responses (bars) against the respective vaccine antigen for each study group; dots indicate individual responses. The RFs in vaccine (V) and placebo recipients (P) are indicated below the bars and in the table. Based on results from [7]. (B) Cross-reactive IgA immune response against CFA/I and CS5-related CFs in ALS specimens collected from Bangladeshi adults and children 24–59 months and SIgA/total SIgA responses in fecal specimens from 6- to 11-month-old infants. Paired pre- and postimmunization specimens from subjects previously shown to have responded to CFA/I [7, 8] were tested for immune responses against corresponding concentrations of CS1, CS14, and for infants (fecal specimens) also against CS17 and specimens from subjects who had previously responded to CS5 [7, 8] were similarly tested for responses against CS7. Fold-rise responses are shown as geometric means (bars). The RFs are indicated below the bars.