Recent clinical experience with vaccines using MPL- and QS-21-containing Adjuvant Systems

Abstract

The immunostimulants 3-O-desacyl-4’-monophosphoryl lipid A (MPL) and the saponin QS-21 are part of licensed or candidate vaccines. MPL and QS-21 directly affect the innate immune response to orchestrate the quality and intensity of the adaptive immune response to the vaccine antigens. The combination of immunostimulants in different adjuvant formulations forms the basis of Adjuvant Systems (AS) as a way to promote appropriate protective immune responses following vaccination. MPL and aluminum salts are present in AS04, and both MPL and QS-21 are present in AS01 and AS02, which are liposome- and emulsion-based formulations, respectively. The recent clinical performance of AS01-, AS02- and AS04-adjuvanted vaccines will be discussed in the context of the diseases being targeted. The licensing of two AS04-adjuvanted vaccines and the initiation of Phase III trials with an AS01-adjuvanted vaccine demonstrate the potential to develop new or improved human vaccines that contain MPL or MPL and QS-21.

Keywords::

• Adjuvant Systems
• AS01
• AS02
• AS04
• immunostimulant
• MPL
• QS-21
• vaccine

Acknowledgements

We thank Matthew Morgan (4 Clinics) for his scientific advice and writing assistance and Ulrike Krause for coordination of the manuscript development.

Financial & competing interests disclosure

Both Nathalie Garçon and Marcelle Van Mechelen are employees of GlaxoSmithKline Biologicals. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Writing assistance was utilized in the production of this manuscript and was funded by GlaxoSmithKine Biologicals.