Tuberculosis Vaccines for Cattle

Bovine tuberculosis (bTB) is a zoonotic disease caused by Mycobacterium bovis that mainly affects cattle. The traditional bTB control strategy is to slaughter animals positive for the official diagnostic test. This method, however, may not be economically feasible in developing countries and is less effective when cattle are in contact with wildlife reservoirs of infection. In these scenarios, cattle vaccination could be an important strategy to control bTB. In this review, we describe the diversified vaccine development against bTB and identify gaps in current knowledge. We discuss progress made in live attenuated (including BCG), inactivated and subunit vaccines tested in preclinical models and field trials. We also provide an overview of existing knowledge in the correlates and biomarkers of protection after vaccination against bTB, as well as the most recent advances in the understanding of the protective immune response against tuberculosis. The similarities between the mechanisms of the immune protection elicited by humans and cattle against TB and bTB, respectively, make any advance in human TB and bTB vaccines mutually beneficial. In accordance with the One Health concept, this mutual benefit is expected to progress in the future.