BCG vaccine and pulmonary tuberculosis

Abstract

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.

Mapping BCG vaccination coverage in Ethiopia between 2000 and 2019

“…The Bacille-Calmette–Guerin (BCG) vaccine is the only vaccine currently available for the prevention of tuberculosis (TB), a bacterial disease that kills more than one million people globally every year [ 1 , 2 ]. The BCG vaccine contains a live attenuated Mycobacterium bovis that can prevent severe forms of TB such as meningitis and disseminated TB [ 3 , 4 ].…”

Immunological Characterization of Proteins Expressed by Genes Located in Mycobacterium tuberculosis-Specific Genomic Regions Encoding the ESAT6-like Proteins

“…Using the Bacillus Calmette Guerin (BCG) vaccine against tuberculosis (TB) has shown variable protective efficacy in different parts of the world [ 1 , 2 , 3 , 4 , 5 ]. In particular, BCG vaccination does not protect against pulmonary tuberculosis in adults [ 6 , 7 , 8 , 9 , 10 , 11 ], which is the major manifestation of the disease in humans as 85% of TB patients have pulmonary disease [ 12 , 13 , 14 ]. Since BCG has antigens cross-reactive with Mycobacterium tuberculosis and the non-tuberculous environmental mycobacteria, the low efficacy or the lack of protection by BCG vaccination is suggested to be due to masking and/or blocking effects [ 15 , 16 , 17 , 18 ].…”