Designing and building the next generation of improved vaccine adjuvants

Vaccine adjuvants interact with the immune system, to increase the potency of vaccine antigens. Many of the adjuvants currently available were developed with little understanding of how they worked. Highly pure recombinant antigens are typically very poorly immunogenic due to a lack of exogenous immune activating components such as nucleic acids, lipids, and cell membrane components. In this review we discuss the role of adjuvants and their role as 'delivery systems' or 'immune potentiators'. We also highlight the need for appropriate delivery of immune potentiators with several 'delivery system' adjuvants such as alum, emulsions, liposomes, and polymeric particles. The challenges faced by vaccinologists to create the next generation of vaccines can be solved in-part by developing a greater understanding of the impact of delivery, and an appreciation of the key role of pharmaceutical sciences.