The advances in brucellosis vaccines.

Brucellosis is a worldwide zoonosis affecting animal and human health. Till now, there is no effective vaccine licensed for brucellosis in humans. Although M5, H38 and 45/20 vaccines were used to prevent animal brucellosis in the early stages, the currently used animal vaccines are S19, Rev.1, S2, RB51 and SR82. However, these vaccines still have several drawbacks such as residual virulence and interfering conventional serological tests. With the development of DNA recombination technologies and the completion of the sequence of Brucella genome, much research focuses on the search for potential safer and more effective vaccines. Preliminary studies have demonstrated that new vaccines, including genetically engineered attenuated vaccines, subunit vaccines and other potential vaccines, have higher levels of protection, but there are still some problems. In this paper, we briefly review the main vaccines that have been used in controlling the brucellosis for decades and the progress in the development of new brucellosis vaccines.