Types of Vaccine Adjuvants

Efforts to develop safe and effective vaccines increasingly involve the use of adjuvants—substances formulated as part of a vaccine to boost immune responses and enhance the vaccine’s effectiveness. NIAID supports a broad portfolio of vaccine adjuvant research, ranging from basic immunology studies to clinical testing of adjuvanted vaccine candidates.

Vaccine adjuvants accelerate, enhance and prolong the immune responses triggered by antigens—the vaccine components that elicit pathogen-specific immune responses. Certain populations, such as people with compromised immune systems, the elderly and the very young, particularly benefit from vaccines with adjuvants because their immune systems may require an extra boost to provide protection. Adjuvants also can allow vaccine developers to use less antigen, which in some cases may be in short supply or costly. Additionally, adjuvanted vaccines can elicit more durable immune responses, reducing or eliminating the need for booster vaccinations.