Tuberculosis remains a public health problem in many regions of the world.
It has been a major cause of morbidity and mortality. Currently, Mycobacterium bovis
bacillus Calmette Guerin (BCG) is the only vaccine which is used to control the spread
of M. tuberculosis infection in humans. However, this vaccine provides a limited
protection against tuberculosis in children. In endemic regions, BCG could not protect
adolescents and adults against M. tuberculosis infection nor prevent evolution to active
disease. Therefore, the development of new vaccines to increase the efficacy of
vaccination against tuberculosis is urgently required. Currently, there are several
preclinical and clinical studies of vaccine candidates. The spectrum of candidates
includes multiple types of subunit vaccines, mycobacteria’s whole cell or extracts
vaccines, live attenuated mutants, vaccines based on delivery by viral vehicles and new
forms of recombinant BCG itself. This chapter reviews the efficacy and failure of the
BCG, and vaccine candidates under clinical development in humans, including those
developed to replace BCG (prime vaccines), to improve immunity promoted by BCG
(prime-boost vaccines), and to decrease the time of chemotherapy (immunotherapeutic
vaccines).
Keywords: BCG, Bacille Calmette-Guérin, Clinical trial, Tuberculosis, Vaccines.
