Background

According to the World Health Organization, tuberculosis (TB) is the world’s leading of death due to an infectious agent and annually causes about 1.5 million deaths. It is estimated that about a third of the world’s population are infected with Mycobacterium tuberculosis (Mtb). Despite significant advances in reducing mortality in recent decades through improved diagnosis and drug treatment regimens, TB still causes enormous human suffering, a major economic burden and is one of the major drivers of global inequity.

The most widely used TB vaccine, the Calmette-Guérin (BCG) vaccine, an attenuated, live culture preparation of the Bacillus of Calmette and Guerin (BCG) strain of Mycobacterium bovis, has been in use for 80 years reaching >80% of children in