A rational vaccine pipeline for tuberculosis.

The development of tuberculosis (TB) vaccines is at a turning point, with the promise of new vaccines on the horizon. Over the next few years, it is possible that we will see a phase III multi-site clinical trial of at least one new TB vaccine and perhaps the introduction of a TB vaccine by the end of the decade. However, many gaps remain in our understanding of TB pathogenesis as well as the host immune responses required to provide protective immunity. A major challenge for TB vaccines is to establish a correlate of vaccine immunity which would greatly facilitate bridging studies needed to approve, license and distribute new TB vaccines in all areas endemic for TB. This will require TB vaccines that are both safe and effective in all populations. It cannot be accomplished without hard work as well as additional resources that match the ambitious goals of the TB community.