Tuberculosis (TB) caused by the intracellular bacterium Mycobacterium tuberculosis (MTB) remains a major worldwide health problem responsible for approximately three million deaths annually. The level of protection conferred by only available TB vaccine, Bacillus Calmette Guerin (BCG) is very variable and differs according to the form of pulmonary TB. For more than 80 years, no new TB vaccine has successfully been developed. With TB eradication on the horizon, new vaccines with better protection rates than BCG or improvement in current immunization program is urgently needed. Vaccine candidates currently in clinical trials include improved recombinant BCG vaccines, virus-based recombinant vaccines, and subunit vaccines comprised of dominant secreted antigens. Secreted proteins, regularly described as culture filtrate proteins (CFPâs), are the main targets of the T-cell response in TB. In recent years, research has been focused on antigens released by live MTB in culture medium; pools of such extracellular antigens have been tested in several laboratories as subunit vaccines with substantial levels of protection in animal models. The demonstration that non-living vaccines based on secreted proteins could effectively protect against subsequent MTB infection in animal models, has led to the initiation of extensive antigen discovery programs which aimed to identify crucial antigenic molecules in culture filtrates.
Last date updated on June, 2014