• 1 January 1977
    • journal article
    • research article
    • Vol. 38  (8) , 1167-1172
Abstract
Cattle which were given virulent A. marginale as a premimmunization procedure or were vaccinated with live attenuated or killed anaplasma preparations were challenge inoculated with virulent A. marginale. Exposure of cattle to virulent or attenuated A. marginale, which induced a strong and lasting cell-mediated response as measured by the leukocyte migration-inhibition test, protected against the development of high parasitemia, anemia and clinical signs of disease after challenge inoculation with virulent A. marginale. Cattle which were vaccinated with killed anaplasma preparations that induced transient and low-level cell-mediated responses were not protected against the development of severe anemia after challenge inoculation although postchallenge parasitemia seemed to be controlled.