QS-21 has been clinically evaluated as a vaccine adjuvant. , it had been tested in more than 3000 patients in 60
clinical trials. Direct, unencapsulated QS-21 is very liable to hydrolyse. It also causes immediate pain at injection site and,
in vitro, causes hemolysis. All of these can be prevented by packaging QS-21 into lipid-based particles, which also have the added advantage of targeting its delivery to
phagocytes. It is part of: • AS-01 (also known as AS01E), GSK's adjuvant used in the
Shingrix vaccine, the
RTS,S vaccine, and the
M72/AS01E vaccine. AS-01 consists of QS-21 and 3-O-desacyl-4'-monophosphoryl lipid A (MPL) sealed inside cholestrol-based
liposomes. •
Matrix-M, Novavax's adjuvant used in the
Novavax COVID-19 vaccine. Matrix-M contains a mixture of soapbark saponins sealed in nanoparticles made of cholesterol and phospholipid; one of these saponins is QS-21. • Immune-stimulating complex (ISCOM) of 1984 and ISCOMATRIX (
CSL Limited, 2012), two forerunners to Matrix-M == Sources ==