The control and eventual eradication of tuberculosis (TB) requires an effective vaccine and reagents for specific diagnosis. The only available vaccine against TB is the bacillus Calmette Guerin (BCG), but the protection imparted by BCG against pulmonary TB in adults varies between nil to 80%. Moreover, the use of BCG vaccination faces two additional problems: i. BCG vaccination induces a delayed type hypersensitivity response that cannot be distinguished from exposure to M. tuberculosis, and therefore it compromises the use of purified protein derivative (PPD) of M. tuberculosis for diagnostic purposes. ii. BCG being a live vaccine is contraindicated in HIV infected individuals for fear of causing disease by itself.