Abstract
Tuberculosis (TB) caused by Mycobacterium tuberculosis infection is responsible for the most deaths by a single infectious agent worldwide, with 1.6 million deaths in 2017 alone. The World Health Organization, through its “End TB” strategy, aims to reduce TB deaths by 95% by 2035. In order to reach this goal, a more effective vaccine than the Bacillus Calmette-Guerin (BCG) vaccine currently in use is needed. Subunit TB vaccines are ideal candidates, because they can be used as booster vaccinations for individuals who have already received BCG and would also be safer for use in immunocompromised individuals in whom BCG is contraindicated. However, subunit TB vaccines will almost certainly require formulation with a potent adjuvant. As the correlates of vaccine protection against TB are currently unclear, there are a variety of adjuvants currently being used in TB vaccines in preclinical and clinical development. This review describes the various adjuvants in use in TB vaccines, their effectiveness, and their proposed mechanisms of action. Notably, adjuvants with less inflammatory and reactogenic profiles that can be administered safely via mucosal routes, may have the biggest impact on future directions in TB vaccine design.
Highlights
Tuberculosis (TB) is responsible for the most deaths by a single infectious agent worldwide, with 1.6 million deaths in 2017 alone [1]
A new TB vaccine will ideally work as an effective booster to Bacillus Calmette-Guerin (BCG) vaccination, as it is unlikely that BCG will be completely replaced in many countries, given its efficacy against severe childhood forms of TB and its apparent ability to reduce pediatric infectious disease deaths more generally, through nonspecific mechanisms [5,6]
As M. tuberculosis infection is a major cause of death in HIV infected individuals, ideally the vaccine should be suitable for immunocompromised individuals for whom BCG is contraindicated [2]
Summary
Tuberculosis (TB) is responsible for the most deaths by a single infectious agent worldwide, with 1.6 million deaths in 2017 alone [1]. The current pipeline of TB vaccine candidates is highly varied and includes live, whole cell inactivated, viral vector and subunit vaccines [3,4]. Antigen expression dynamics may be crucial for generating effective immunity and whole-cell killed vaccines, and while they express many antigens, they may not express enough of the right antigens for robust protection [8]. Live vaccines, such as viral vectored, modified BCG, and attenuated M. tuberculosis, are being trialed. This review focuses on adjuvants and delivery systems for use in novel subunit TB vaccines, their mode of action, and likely impacts on the anti-TB immune response
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
