Improved disease resistance after Babesia divergens vaccination.

The efficacy of a new inactivated vaccine against Babesia divergens was evaluated by means of inoculation tests. The infection was initiated by i.v. injection of blood containing 2 x 10(9) living parasites into splenectomized and non-splenectomized calves. Clinical status and hematological parameters were determined. Serology examinations for antibodies against B. divergens were carried out by indirect fluorescent antibody test (IFAT). Non-vaccinated and splenectomized animals exhibited experimental infections. In vaccinated and splenectomized animals, clinical symptoms and prolonged incubation periods were observed.