Evaluation of the cell-mediated immune response to reduced doses of Mycobacterium avium ssp. paratuberculosis vaccine in cattle.

Vaccination against Johne's disease with an inactivated, oil-adjuvanted Mycobacterium avium ssp. paratuberculosis (MAP) bacterin can reduce clinical signs in infected herds; however, the development of indurated swelling at the injection site limits vaccine acceptability to producers. This study determined whether a reduced dose of vaccine antigen, with a full dose of adjuvant, would produce comparable T cell-mediated immune responses with smaller lesions.