For active immunisation of cattle to reduce kidney colonisation and shedding of Leptospira borgpetersenii serovar Hardjo type hardjobovis to the extent that no viable organisms can be detected by culture in the urine of vaccinated animals after challenge. A 3 week onset of immunity and 12 month duration of protection has been demonstrated by challenge with Leptospira borgpetersenii serovar Hardjo type hardjobovis. For active immunisation of cattle persistently infected with Leptospira borgpetersenii serovar Hardjo type hardjobovis. Vaccination reduces urinary shedding of Leptospira borgpetersenii serovar Hardjo type hardjobovis without clearance of renal colonisation. This effect appears 4 weeks post vaccination and its duration is unknown. The epidemiological significance of the reduced shedding has not been demonstrated. The vaccination may not prevent abortion in cows in which placental infection has already occurred.
