QS21

**Semantic type:** Organic Chemical|Pharmacologic Substance

**Definition:** A purified, natural saponin isolated from the soapbark tree Quillaja saponaria Molina with potential immunoadjuvant activity. When co-administered with vaccine peptides, QS21 may increase total antitumoral vaccine-specific antibody responses and cytotoxic T-cell responses.

**Synonyms:** - NIAID VEU 016 - Purified Quillaja Saponin - QS-21 - QS-21 Adjuvant - QUILLAJA SAPONIN (QS-21) - Stimulon QS-21 Adjuvant