Towards new tuberculosis vaccines.

According to WHO, about one third of the world's population is infected with bacteria of the Mycobacterium tuberculosis complex. Currently there is globally 9.15 million recorded cases of overt tuberculosis (TB) annually and due to lack of adequate diagnostics presumably a large but unknown number of non-recorded cases. TB is estimated to cause 1.65 million deaths per annum which accounts for one-fifth of all deaths by infectious diseases of adults in low-income countries. During recent years a rapid spread of multi-drug resistant bacteria causing about 0.5 million TB cases per year has worsened the problem. The live attenuated Bacillus Calmette-Guérin (BCG) vaccine which is the only currently available TB vaccine does not confer any significant protection against the most common and contagious form of TB-adult pulmonary TB.