Recent Advances in Tuberculosis Vaccine Development

Mohd-Nor      Norazmi; Maria   E.   Sarmiento; Armando      Acosta

Abstract

Tuberculosis is exacting a great toll on the lives of many people worldwide. Despite seemingly previous successes in controlling the disease, tuberculosis is now re-emerging as the leading cause of mortality due to infectious diseases in many parts of the world. The high incidence of the disease has been attributed mainly to its combination with HIV infection and the emergence of multi-drug resistant strains. In addition, the low diagnostic reliability and therapeutic coverage, as well as the absence of a fully protective vaccine, configure the current situation of the disease at a worrying level. Taking into account these antecedents, it is considered that the development of an effective vaccine is the most important and urgent element for the control of the disease. Supported by the better understanding of the immune response to the infection, the biology of Mycobacterium tuberculosis and the availability of new technologies in genomics and proteomics, a wide range of experimental vaccines have been attempted. These approaches include the use of inactivated strains; live genetically attenuated strains; live vectors expressing M. tuberculosis antigens; recombinant subunits, conjugated, and DNA vaccines as well as the combination of selected strategies in prime boost immunisations. Furthermore, the use of novel adjuvants, delivery systems and routes of immunisation have also been evaluated. Some of the candidate vaccines demonstrated significant levels of efficacy in animal models and are now in initial clinical evaluation. This review analyzes the main aspects related to the development of new generation vaccines against tuberculosis, as well as the challenges and complexities inherent to this endeavour.

Keywords: bcg, conjugated vaccine, dna vaccine, inactivated vaccine, live attenuated vaccine, prime boost immunisation, recombinant vaccine, subunit vaccine, tuberculosis