Degree of oviduct dilatation after vaccination and chlamydial challenge. Animals (six mice/group) were immunized with three doses of rCPAF+IL-12, rMOMP+IL-12, rIncA+IL-12, rCPAF+rMOMP+IL-12, rCPAF+rIncA+IL-12, rCPAF+rMOMP+rIncA+IL-12, HEL+IL-12, and PBS (mock immunized). One month after the final booster vaccination, mice were challenged i.vag. with 105 IFU of C. muridarum. At day 80 following challenge, animals were euthanized and their genital tracts were processed and stained with hematoxylin and eosin. The degree of oviduct dilatation was measured and expressed as the ratio of oviduct diameter to wall thickness for each mouse and as the mean ratio ± standard error for each group. The oviduct dilatation ratio differed significantly between the experimental groups (P < 0.001 by ANOVA). rCPAF+IL-12, rCPAF+rMOMP+IL-12, rCPAF+rIncA+IL-12, and rCPAF+rMOMP+rIncA+IL-12 each demonstrated significantly reduced dilatation compared to PBS (mock immunized) (P < 0.05).