vaccines and vaccine candidates against brucellosis

brucella is a facultative intracellular pathogen, and brucellosis is commonest zoonotic disease worldwide. brucella species, isolated from domestic animals, are important pathogen for humans. annually, more than 500,000 new cases of brucellosis are reported, and this figure is an underestimate due to extended under-reporting cases in several endemic countries. brucella has a variety of virulence mechanisms that prevent detection and activation of innate immunity, but protection against intracellular pathogen is represented by cell-mediated immunity. as yet, much research has been performed to develop a safe brucella vaccine to control the disease in human and animals. despite the availability of several live attenuated vaccine for animals, currently, no effective human vaccine is available. moreover, due to the potential use of brucella in bioterrorism or biowarfare, development of an effective vaccine against brucellosis for human use is necessary. in this paper, we aimed to review and discuss the efforts of researchers to develop vaccines against brucellosis.