BCG vaccine and pulmonary tuberculosis

Tuberculosis (TB) is one of the most important public health problems in the world and has been declared as a global emergency by the World Health Organization (WHO) in 1993. Bacillus Calmette-Guérin (BCG) is one of the first developed vaccines to prevent TB. Unfortunately, BCG vaccine has had a limited duration of protection and has shown controversial and variable levels of efficacy, especially against pulmonary TB. On the other hand, efforts in production of new forms of this vaccine have been in vain and revaccination is not considered as a suitable strategy to control the disease. Considering that TB affects adults mostly between the ages of 15 and 59, pulmonary TB is more common than disseminated TB and BCG vaccine has had a minimal effect on the global burden of pulmonary TB. Before introducing a new, safe and effective vaccine, combined strategies in the field of control and treatment of TB rather than vaccination are necessary.