Clinical evaluation of adjuvants

Publisher Summary This chapter reviews the clinical evaluation of adjuvants in vaccine development. It reviews definitions, qualities of an ideal adjuvant, and components of adjuvant development, and discusses regulatory issues as well as examples of licensed and experimental adjuvants in human vaccines. Adjuvants typically have complex and multifactorial immunological mechanisms of action in vivo. Adjuvant safety, including the real and theoretical risks of administering vaccine adjuvants to humans, is a critical component that can enhance or retard the development process. In addition to the problem of safety, other preclinical issues critical to orderly clinical development of adjuvanted vaccines are—variable adjuvanticity, suboptimal use of aluminum adjuvants, inadequate animal models, and the inability to predict consistently protective or therapeutic efficacy by immunoassays. Experimental adjuvants in clinical trials include safer exotoxins, oligonucleotides, derivatives of lipid A other than monophosphoryl lipid (MPL), cytokines, dendritic cells, saponins, montanides, nonionic block copolymers, polyactide (PLG), and combination adjuvants such as AS04.