The Modes of Action of Vaccine Adjuvants

Globally, vaccines are the most effective medical interventions in limiting morbidity and mortality against infections. Effective vaccines are administered in a variety of formulations and include not only portions of their target but also adjuvants. Adjuvants can improve the magnitude and breadth of the immune response and immunological memory against the target and also determine the nature of the generated immune response. Almost all vaccines that are now in use include adjuvants, such as nucleic acids from the target organisms, in the case of attenuated virus vaccines, insoluble aluminum salts (alum), oil-in-water emulsions (MF-59) or formulated toll-like receptor ligands (MPL-TLR4). However, the world still lacks consistently effective vaccines against many infectious agents, tuberculosis, malaria and HIV and against cancers. Therefore much current research is devoted to identification of newer adjuvants, adjuvants that will safely induce the type of immune response that will most effectively deal with its target. In many cases the precise mode of action of the adjuvant is not known. For example the mode of action of alum, an adjuvant that has been used in vaccines since the 1930s and generates excellent antibody responses, is still inadequately understood. This conference will focus on the cell and molecular mechanisms of action of old and new adjuvants and other immunomodulatory agents and their use in various vaccines against infectious diseases and cancer.