ChEBI

A substance that augments, stimulates, activates, potentiates, or modulates the immune response at either the cellular or humoral level. A classical agent (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contains bacterial antigens. It could also be endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Its mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy is related to its antigen-specific immunoadjuvanticity.