Vaccination of Cattle
Brucella abortus is a bacterium that causes brucellosis in cattle.
B. abortus RB51 is a strain of this bacterium developed specifically for immunization of cattle against brucellosis to allow serological differentiation between naturally infected and vaccinated animals.
Accidental human exposure to RB51, though uncommon, has resulted in development of symptoms consistent with brucellosis. Exposures have included needle sticks, eye and wound splashes, and contact with infected material.
Other vaccines, such as Brucella abortus S19 for cattle and B. melitensis Rev-1 for sheep and goats, can also cause infection in humans.
Veterinarians and other medical staff performing immunizations in cattle should be aware of the risks and what to do when an exposure occurs. S19 and Rev-1 exposures should follow the same assessment guidance as for RB51. Serological monitoring is available for S19 and Rev-1 exposures.