Evaluation of vaccines against ovine dermatophilosis.

Intradermal vaccination of live crude filaments (vaccine A) was compared with a vaccine (vaccine B) consisting of a 45 kD zoospore protein and mucoid material coating filaments in its ability to protect sheep from experimental Dermatophilus congolensis infection. Fourteen and 21 days after challenge, vaccine A sheep had fewer lesions (P less than 0.001) than the vaccine B sheep. The lesions on the vaccine A sheep were also less severe 14 and 21 days after challenge (P less than 0.05, P less than 0.01 respectively). In a second study, vaccine A was assessed for its ability to protect against natural challenge. Ten weeks after contact with sheep with active and generalised dermatophilosis no difference was found between the number of lesions present on the vaccine A and unvaccinated sheep and no differences were found in the number of sheep in each group with active lesions.