Experimental evaluation ofbacterin against a Koreanchallenge.

Abstract

The objective of this study was to evaluate the efficacy of a newbacterin against a Koreanchallenge under experimental conditions. Fifteen pigs were allocated randomly into 3 groups (5 pigs per group) that were designated in 1 of 3 ways: vaccinated-challenged, unvaccinated-challenged, or unvaccinated-unchallenged. The pigs in the vaccinated-challenged group were immunized with anwhole-cell bacterin at a 1.0 mL dose-level at 21 d old. At 42 d old (0 d post-challenge), the pigs in the vaccinated-challenged and unvaccinated-challenged groups were inoculated intranasally with a strain of Korean. Vaccinated-challenged pigs elicited a strong cell-mediated immunity as measured by-specific interferon-γ secreting cells when compared with unvaccinated-challenged pigs. Vaccination of pigs with this newbacterin reduced nasal shedding and lung lesions. The evaluated vaccine was therefore considered effective in controllinginfection.