Fig 1.

Immune responses to PA-adjuvant vaccine formulations. PA-specific IgG endpoint titers (A and D) and LTx neutralizing antibody titers (ED₅₀) (B and E) were determined by ELISA and toxin neutralization assay, respectively, in individual serum samples of rabbits immunized with PA+HLT by the TCI route (A and B) or with PA-adjuvant vaccine formulations by the i.m. route on weeks 0, 4, and 8 (D and E). Data represent means ± standard errors of the means. Kaplan-Meier survival curves for rabbits challenged with 100 LD₅₀ Ames strain spores on week 14 (C) or 19 (F) of the study are shown. ∗, P ≤ 0. 0.01.