Fig. 1: Day 21 serum HAI titres.

BALB/c mice (n = 10 per group in two separate experiments) were immunized via IM injection with CfaEB, dmLT, and SLA formulated in SE. a Serum was collected on Day 21 and HAI conducted with human red blood cells using ETEC strain H10407. b The 14 point model based on the black and grey points accurately predicts the HAI titres observed for the two test points indicated in open circles. The non-parametric Spearman correlation coefficient r is shown. c A 10 component model was fitted to the 16 observed data points incorporating main, curvature, and pairwise interaction effects. Surface responses are shown as a function of d CfaEB vs. SLA at 0.17 µg dmLT, e CfaEB vs. dmLT at 0.5 µg SLA, f SLA vs. dmLT at 1.7 µg CfaEB. g HAI titres were determined as in a for animals immunized with the LSQ, AF or Al formulations and the titres for the maximal dose vaccines for each formulation are shown. h The observed range of HAI responses and dose composition (µg) for each optimal vaccine composition are shown by formulation. Grey data points indicate the maximal dose vaccine composition. Open circles indicate the two test vaccine compositions. Lines represent geometric means and whiskers indicate the 95% confidence intervals. Statistical analysis was performed with Student’s T test, or one-way ANOVA with Tukey’s multiple comparisons post-test (two-sided). *p < 0.05; **p < 0.01.