Protective immunity conferred by mucosal vaccination.

<p>Animals (n = 6 per group) were vaccinated either i.t. (panel A) or orally (panel B) with either 10⁵ CFU U112, 10⁷ CFU U112Δ<i>iglB</i>, or mock-vaccinated with PBS and rested for 30 days. Rats were challenged i.t. with 1.25×10⁴ CFU SCHU S4 (approx. 25 LD₅₀) and monitored daily for morbidity and mortality. Kaplan-Meier survival analysis revealed protection following immunization with U112 by both i.t. and oral routes were significant (<i>p</i><0.001 and <i>p</i><0.005, respectively) over mock immunization. Protection conferred by U112Δ<i>iglB</i> vaccination was significant over mock control (<i>p</i><0.01 (i.t.) and <i>p</i><0.005 (oral)). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047639#s3" target="_blank">Results</a> are representative of two independent experiments.