A note on adult sheep vaccination with reduced dose of Brucella melitensis Rev 1

This work describes results obtained by vaccinating pregnant ewes from a Brucella melitensis-infected flock, with 5 x 10(8) CFU (half dose) Rev 1. Only five abortions were recorded after vaccinating 600 pregnant ewes. The serological response was followed by rose bengal, complement fixation and radial immunodiffusion tests. A short-termed, low humoral immunoresponse was produced. The radial immunodiffusion test could be more useful than the other tests for differentiating infected from vaccinated sheep. It was concluded that vaccination with 5 x 10(8) CFU Rev 1 seems to have little or no effect on the normal development of pregnancy.