Vaccination strategies to prevent tuberculosis in the new millennium: from BCG to new vaccine candidates.

Current global control efforts targeting tuberculosis (TB) include the treatment of latent TB infection, case detection and treatment with directly observed therapy short-course (DOTS), and BCG (bacille Calmette-Guérin) vaccination. However, BCG has been found to decrease only childhood TB morbidity and mortality but has a very limited effect in the transmission dynamics of the infection. These limitations of BCG are the driving force for the development of new TB vaccines. New TB vaccine candidates have entered clinical evaluation and many more are in the pipeline to undergo clinical testing. New vaccine candidates may offer better protection than that afforded by currently available BCG vaccines. Furthermore, combined vaccination schedules against TB seem to be a promising strategy in the new millennium.