DNA vaccine encoding L7/L12-P39 of Brucella abortus nduces protective immunity in BALB/c mice

Brucella abortus is a gram-negative, facultative, intracellular bacterium that infects both cattle and humans, causing abortion and infertility in the former and undulant fever, endocarditis, arthritis, and osteomyelitis. Resistance to Brucella depends on acquired cell-mediated immunity （CMI）. Live attenuated vaccines can stimulate strong CMI response, which are usually very effective against brucellosis and are used to control brucellosis in domestic animals. However, there is no safe and effective vaccine available for human because the vaccine strains used for animals are considered too virulent for humans. A vaccine that will be noninfectious to humans but effective in stimulating a broad protective immune response is needed.