Vaccine Adjuvants

About Vaccine Adjuvants

Vaccine adjuvants are substances that enhance the immune response to vaccine antigens. Aluminum salts alum were the first adjuvants, used since the 1920s. Alum remains the most widely used adjuvant. The mechanism of alum adjuvants was unknown for decades. MF59, an oil in water emulsion developed by Chiron and later owned by Novartis and CSL Seqirus, was first licensed in 1997. AS01, used in the Shingrix and M72 vaccines, contains MPL and QS 21. Pandemrix, an AS03 adjuvanted pandemic H1N1 vaccine, was associated with an increased risk of narcolepsy, particularly in children and adolescents in Finland and Sweden. Matrix M, developed by Novavax, uses saponin from the Quillaja saponaria tree. Adjuvants can reduce the amount of antigen needed, which is critical during pandemics. The development of new adjuvants is challenging due to safety concerns and the complexity of immune responses.