Recent developments in vaccination against bovine brucellosis.

Recent research in vaccination against bovine brucellosis has been directed towards reducing the serological response to vaccination and to developing serological tests better able to distinguish vaccinal titres from those resulting from field infection. In the case of strain 19 vaccination, developments such as reducing the dose of vaccine and improving serological tests have so reduced the serological response as to allow adult vaccination to be carried out in combination with eradiction by test and slaughter. B. abortus 45/20 vaccine is being increasingly used as a combined diagnostic aid and protective agent. Progress has been made in identifying antibodies produced in response to this vaccine.