Novel adjuvants and delivery systems for enhancing immune responses induced by immunogens

Vaccines are the most important preventive measure against infectious diseases. In developing an effective vaccine, besides the primary challenge of identifying the most relevant immunogen and efficient regime of immunization, selection of a potent adjuvant and delivery method is equally critical. The formulation of immunogens with different adjuvants may affect the affinity maturation of antibody responses differently, suggesting that the structure of specific epitopes within the immunogen may be influenced by different adjuvants. Thus, developing adjuvants that can efficiently activate both the innate and adaptive arms of the immune system is a major challenge for vaccine researchers. The use of novel adjuvants in combination with novel immunogen design holds great promise towards the goal of enhancing the potency, breadth and durability of vaccines. This article summarizes the different immunopotentiators (and immunomodulators) as well as the delivery systems that are available for vaccine generation and the types of immune responses that each of them induces. Also discussed are adjuvants that have a combination of both immunomodulatory and delivery properties.