New‐Generation Vaccine Adjuvants

Abstract

Abstract The currently available vaccines represent an outstanding success story in modern medicine, as they are responsible for a huge reduction in morbidity and mortality worldwide. However, it is clear that new approaches are necessary to enable the development of vaccines against more difficult pathogens, which are not yet under control, including human immunodeficiency virus (HIV), malaria and Methicillin‐resistant Staphylococcal aureus (MRSA). In addition, vaccines are necessary to counter emerging pathogen threats such as pandemic influenza and Ebola viruses. Potential improvements to current vaccines may include the addition of new adjuvants, which are able to induce more potent immune responses, more rapid responses or responses with an expanded breadth of pathogen coverage. New‐generation adjuvants are now becoming available which may enable the development of new and improved vaccines, and this is currently a very active area of research and development. Key Concepts Vaccines are safe and effective and have had a major impact on reducing the impact of infectious diseases in the twentieth century and continue to do so early in the twenty‐first century. Adjuvants are included in vaccines to increase the immune response to the vaccine antigens. Vaccine adjuvants are often necessary to enable vaccines to be effective. Most currently available childhood vaccines contain insoluble aluminium salts as adjuvants. To enable the development of vaccines against some more difficult pathogens, such as HIV and malaria, more potent adjuvants will be required. New‐generation adjuvants normally comprise several components combined together to achieve the best immune response to the vaccine. New vaccine adjuvants will have to undergo extensive safety testing before they will ever be included in licensed vaccines. Recently, it was identified that traditional small molecular weight drugs could perform as adjuvants, opening up the possibility of discovering many more new adjuvant‐active compounds. Formulation science is a key contributor to allow the development of safe and effective vaccine adjuvants. It is becoming increasingly important to fully understand the mechanism of action of vaccine adjuvants, how they work is important.