title: Prospects in Mycobacterium bovis Bacille Calmette et Guérin (BCG) vaccine diversity and delivery: why does BCG fail to protect against tuberculosis?
abstract: Mycobacterium tuberculosis (M.tb) infection leads to active tuberculosis (TB), a disease that kills one human every 18s. Current therapies available to combat TB include chemotherapy and the preventative vaccine Mycobacterium bovis Bacille Calmette et Guérin (BCG). Increased reporting of drug resistant M.tb strains worldwide indicates that drug development cannot be the primary mechanism for eradication. BCG vaccination has been used globally for protection against childhood and disseminated TB, however, its efficacy at protecting against pulmonary TB in adult and aging populations is highly variable. In this regard, the immune response generated by BCG vaccination is incapable of sterilizing the lung post M.tb infection as indicated by the large proportion of individuals with latent TB infection that have received BCG. Although many new TB vaccine candidates have entered the development pipeline, only a few have moved to human clinical trials; where they showed no efficacy and/or were withdrawn due to safety regulations. These trials highlight our limited understanding of protective immunity against the development of active TB. Here, we discuss current vaccination strategies and their impact on the generation and sustainability of protective immunity against TB.
authors: Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, US.
authors: Juan I
authors: JI
authors: Moliva
authors: Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, US; Center for Microbial Interface Biology, The Ohio State University, Columbus, OH 43210, US.
authors: Joanne
authors: J
authors: Turner
authors: Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH 43210, US; Center for Microbial Interface Biology, The Ohio State University, Columbus, OH 43210, US. Electronic address: jordi.torrelles@osumc.edu.
authors: Jordi B
authors: JB
authors: Torrelles
mesh_terms: D001500:BCG Vaccine / Q000276:immunology*; D002986:Clinical Trials as Topic; D006801:Humans; D009163:Mycobacterium bovis / Q000276:immunology*; D014376:Tuberculosis / Q000517:prevention & control*
chemical_list: D001500:BCG Vaccine
keywords: Mycobacterium bovis Bacille Calmette-Guérin (BCG); Mycobacterium tuberculosis; Tuberculosis; Vaccine