Is intranasal vaccination a feasible solution for tuberculosis?

Bacille Calmette-Guerin (BCG) vaccine has been the only licensed tuberculosis (TB) vaccine administered to humans and, until today, more than 3 billion people have received BCG. However, despite the use of BCG, TB remains a global epidemic with a third of the world population being infected. Regardless of the protection induced by BCG in childhood TB, BCG vaccination fails to protect against pulmonary TB in adults, which represents more than 85% of the total TB burden. Therefore, the development of safe and efficacious TB vaccines that can confer potent protection in the lung mucosa has remained a major challenge to TB vaccinologists. Intranasal vaccination by different antigen formulations has shown promising results in the augmentation of immunity and the combat of the pathogens at the site of infection. This article will focus on the potential of intranasal vaccination and mucosal adjuvants for the development of new-generation TB vaccines.