Improvements in adjuvants for new-generation vaccines

Abstract

Over the last decade, extensive research for development of new vaccine adjuvants is being carried out. Present generation vaccines, particularly those based on recombinant proteins and DNA, are not only less reactogenic and also less immunogenic. Therefore, there is an urgent need for the development of new and improved vaccine adjuvants. Many novel adjuvants have been cleared for license, and many are in late stages of clinical trials. Recent investigations in innate immunity have offered new insights into immunostimulatory actions of adjuvants and have facilitated a more rational selection of adjuvants. Despite the impressive response of approved adjuvants in generating immunity against pathogens, there remains a need for improved adjuvants that enhance strong T-cell immunity and protective antibody response. The discovery of more potent adjuvants will also allow engineering of vaccines against infections that do not naturally elicit protective immunity. A logical approach to the development of new and more effective vaccine adjuvants requires a better understanding of the action of adjuvant-antigen formulations. Here, we discuss these advances and the need for better adjuvant development.