FIG. 1.

Mean log₂ serum anti-CN IgG antibody titers. Rabbits were vaccinated (on days 7, 21, and 35, except for groups receiving PMT, which were vaccinated on days 7 and 35) either i.n. or s.c. with either PMT or CN alone or in combination with each other (PMTCN) or with a control (Co) (aluminum hydroxide for s.c. administrations and saline for i.n. administrations). Serum samples were collected prior to vaccination, 1 week after each vaccination, and 3 days following challenge. Rabbits were challenged i.n. with virulent P. multocida on day 49. Samples were analyzed by an ELISA as described in Materials and Methods. Between- and within-group interactions were analyzed by MANOVA, with a P value of <0.05 being considered statistically significant. Lowercase letters signify comparisons made between groups, with different letters signifying statistical significance between groups at each time period. Vacc, vaccination.