Secondary Outcomes
Measure: Occurrence of vaccine-related serious adverse events (SAEs)
Time: Day 1 through 6 months following last vaccination
Measure: Occurrence of vaccine-related, non-solicited adverse events (AEs)
Time: Day 1 through 6 months after last vaccination
Measure: Proportion of subjects with > / = 2-fold rise from the baseline in double mutant heat-labile toxin (dmLT)-specific toxin neutralization IgA-ALS titers at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Measure: Proportion of subjects with > / = 2-fold rise from the baseline in double mutant heat-labile toxin (dmLT)-specific toxin neutralization IgG-ALS titers at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Measure: Proportion of subjects with > / = 4 fold rise from the baseline double mutant heat-labile toxin (dmLT)-specific fecal IgA titers at any time
Time: Day 1 through 8 days (cohorts 5A and 5B) or 29 days (cohorts 1-4 and 5C) following last vaccination
Measure: Proportion of subjects with > / = 4 fold rise from the baseline ratio of antigen-specific IgA over total IgA at any time
Time: Day 1 through 8 days (cohorts 5A and 5B) or 29 days (cohorts 1-4 and 5C) following last vaccination
Measure: Proportion of subjects with > / = 4-fold rise from the baseline in double mutant heat-labile toxin (dmLT)-specific serum IgA titers at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Measure: Proportion of subjects with > / = 4-fold rise from the baseline in double mutant heat-labile toxin (dmLT)-specific serum IgG titers at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Measure: Proportion of subjects with > / = 4-fold rise from the baseline in the ratio of double mutant heat-labile toxin (dmLT)-specific toxin neutralization titer at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Measure: Proportion of subjects with > 8 IgA-ASC/10^6 peripheral blood mononuclear cells (PBMCs) at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Measure: Proportion of subjects with > 8 IgG-ASC/10^6 peripheral blood mononuclear cells (PBMCs) at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Description: Determined by EliSpot
Measure: Proportion of subjects with B or T cell memory at any time
Time: Day 1 through 56 days (Cohorts 1-4) or 6 months (Cohort 5) following last vaccination
Measure: Proportion of subjects with IgA double mutant heat-labile toxin (dmLT)-specific circulating ASC expressing gut homing receptors (integrin alpha4beta7 in the absence or presence of CD62L) at any time in cohort 5 only
Time: 8 days following first vaccination through 8 days following last vaccination
Measure: Proportion of subjects with IgG double mutant heat-labile toxin (dmLT)-specific circulating ASC expressing gut homing receptors (integrin alpha4beta7 in the absence or presence of CD62L) at any time in cohort 5 only
Time: 8 days following first vaccination through 8 days following last vaccination