Fig. 4.

SLA-SE augments systemic serum IgG2 responses to CfaEB and dmLT. BALB/c (n = 5 per group, per experiment) were immunized as in Fig. 1. Serum samples were collected on Day 21 after the priming immunization (a, c) and 14 days after the booster immunization (b, d). Serum samples assessed for CfaEB-specific (a, b) or dmLT-specific IgG2a (c, d) by ELISA and log₁₀ transformed. e Horizontal bars are drawn at the mean. The lower limit of detection (LOD) is indicated by the dashed line. Data pooled from two experiments indicated with open and closed symbols, respectively, with similar results. *, **, ***, and **** indicate P < 0.05, 0.01, 0.001, and 0.0001, respectively, as determined by one-way ANOVA using Tukey’s multiple comparisons test. All other pairwise comparisons between the groups were not significantly different