Intestinal immunity
All positive fecal neutralization responses occurred after bOPV challenge except for one response in the IPV group before bOPV challenge (Presence of fecal type-specific poliovirus neutralization activity in the three study groups. Shown as percentages of each group with detected activity with 95% CI bars.As with the fecal neutralizing responses, only a small proportion of participants demonstrated any measurable changes in fecal IgA over time. Generally, higher levels of fecal IgA were observed when measured using the Sabin strains which also resulted in more variable results than the Salk strains. However, fecal IgA levels using the Salk strains were higher in the IPV group compared with the IPV + dmLT group, particularly for serotypes 1 and 2, and on Day 29.No meaningful differences were observed in IgG (Proportions with type-specific circulating IgG antibody-secreting cells (ASC) by timepoint in each per protocol study group.Proportions with type-specific IgA antibody-secreting cells (ASC) by timepoint in each per protocol study group.Few αProportions with type 1-specific circulating IgA and IgG-secreting α4β7 ASC Homing Marker 7 days after vaccination (Day 8) or bOPV-challenge (Day 29) in each per protocol study group striated according to expression (neg, dim and high).Positive homing IgG ASC responses was more widespread, with observed responses to all three poliovirus types, the proportions of participants with α