*Isolated from closed cases of [[Bursae and Tendons Inflammatory - Pathology#Poll Evil and Fistulous Withers|poll evil and fistulous withers]] in horses
+
+
Vaccination of heifers against ''B. abortus'' in endemic regions by Strain S19, a live attenuated vaccine, stimulating a cell-mediated immune response. The vaccination of young animals interferes with serological testing. The 45/20 bacterin vaccine is less effective and the newer RB51 vaccine has no LPS O-antigen therefore not detected by serological tests and gives good protection.