Towards a new vaccine

Despite extensive administration of the BCG vaccine to infants throughout the world, the global TB epidemic continues, with TB representing the world's leading infectious cause of death. Developing a TB vaccine capable of preventing TB disease, primarily in adolescents and adults, the most important sources of Mycobacterium tuberculosis spread, represents a critical need in efforts to stem the global TB epidemic, including the spread of M. tuberculosis strains resistant to multiple TB drugs. 13 TB vaccine candidates are currently in clinical trials. Results from two recently completed trials have demonstrated protective efficacy, and new broader strategies to TB vaccine development, including the diversification of M. tuberculosis antigens, vaccine platforms and routes of vaccine administration are being pursued. In this chapter, we review the current status of the TB vaccine pipeline as well as the future directions in the critically important effort to develop new TB vaccines.