Chapter 5 - Vaccine delivery systems against tuberculosis

Abstract

Tuberculosis (TB) is a life-threatening contagious disease, which hastily affects the worldwide population. Contextually, the development of TB vaccines has made a notable achievement by improving vaccine efficacy and immunogenicity. The exiting bacillus Calmette-Guerin vaccine has shown partial efficacy against the Mycobacterium tuberculosis, but its immunogenicity diminishes with the time. Currently, several TB vaccines have been designed and are in the different phases of clinical trials. However, there are many factors which may lead to the failure of these vaccines and one of the parameters could be the vaccine delivery systems. It is the route of vaccine delivery which decides the fate of a vaccine that whether adequate and robust immune responses will be generated or not. Therefore adjuvants and immunogenic carriers are used in conjugation with a vaccine to enhance the humoral as well as cell-mediated immunity. The delivery systems need to deliver the vaccines at the immune-privileged sites, which directly associated with the lymphoid organs and hence initiate the various signaling cascades for the elimination of the pathogen. The advanced target-based TB vaccine delivery system uses the nanoparticles, liposomes, ISCOMs, and VLPs to acquire the potential immune response. The advantages of these delivery systems include the protection of antigens from the proteolytic degradations, provide an extended immune response, and have the ability to encapsulate multiple antigens at a time along with the determination of vaccine efficacy.