AS04 Adjuvant

**Semantic type:** Pharmacologic Substance

**Definition:** A proprietary vaccine adjuvant composed of the inorganic compound aluminum phosphate mixed with 3-deacylated monophosphoryl lipid A, a derivate of the bacterial endotoxin. The aluminum component of this adjuvant binds to the protein conjugate, resulting in improved antigenicity, whereas the modified lipid A component enhances the immune responses by activating monocytes, macrophages and cytokines. Combined with vaccine antigens, AS04 adjuvant may help to boost the host's immune responses.