Aluminum Adjuvants: Basic Concepts and Progress in Understanding

Abstract

More than 80 years have passed since the initial discovery that aluminum salts, when injected together with an antigen, resulted in highly elevated specific antibody titers. Since then the aluminum adjuvants have achieved an undisputed status as the most commonly used adjuvants in human and veterinary vaccines. The present chapter compiles historical data on aluminum adjuvants from the very early start and data made obtainable thanks to the development of analytical tools for providing general insight into the mechanisms of the immune system. Applying these tools in adjuvant research have helped characterizing the aluminum adjuvants in terms of isotypic profiles, surface marker expression profiles, cytokine profiles and within the latest 5 years with the discovery of the NALP3 inflammasome its importance for the secretion of interleukin (IL)-1β and IL-18 as pro-inflammatory mediators in the early phases of the immune response. For decades very little was known about the mechanisms of action of aluminum adjuvants, and their use in vaccine design was predominantly based on empirical principles. The results from applying such analytical tools are about to take us to the next level of understanding aluminum adjuvants.