FIG. 2.

Summary of mean lesion scores for birds from all immunized groups across different experiments, together with those for the concurrent unimmunized controls. VC, vehicle-only controls, A-tox, alpha-toxin; Sup, culture supernatant of C. perfringens; G+H, combination of GPD and HP; Exp, experiment; +, the birds in this group were challenged for 3 days and necropsied on day 6; ++, the birds in this group were given a severe challenge, like the one used in experiment 3; *, the immunized group had significantly fewer chickens with lesions than the unimmunized vehicle-only control group (Fisher's exact test, P ≤ 0.05).