MTBVAC: A Tuberculosis Vaccine Candidate Advancing Towards Clinical Efficacy Trials in TB Prevention.

Tuberculosis (TB) remains a major global health burden, causing more than 10 million new cases and 1.6 million deaths each year. Currently, the only approved TB vaccine in use in humans, is the one hundred years old vaccine, BCG, an attenuated vaccine derived from an isolate of Mycobacterium bovis that causes TB in cattle. BCG shows a variable efficacy in preventing pulmonary forms of the disease in humans, so new vaccines are needed to help stop TB transmission. Among the 15 diverse TB vaccine candidates in clinical trials, MTBVAC is the only one based on rational attenuation of a human clinical isolate of Mycobacterium tuberculosis, which contains the largest number of antigens of the TB vaccine candidates in the pipeline. MTBVAC was designed and constructed as a response to the need to confer a better TB protection in terms of pulmonary disease prevention in newborns, adolescents, and adults. This review aims to provide an overview of the preclinical and clinical development of MTBVAC to the present. We will focus on the clinical development of MTBVAC, and we will compare it with other TB vaccine candidates currently in Phase 3 efficacy trials.