Methodological considerations: Potency tests for recombinant adjuvanted RTS,S vaccine

Overview

Adjuvanted recombinant RTS,S-based vaccines have been in clinical evaluation since the late 1980s and various adjuvant formulations have been evaluated. The final formulation evaluated in Phase III confirmatory trials is RTS,S adjuvanted with AS01 proprietary adjuvant system. There is currently no International Standard suitable for the standardization of assays of vaccines from the manufacturer. The manufacturer has therefore established a product-specific reference preparation which is traceable to a lot of vaccine shown to be efficacious in clinical trials. This vaccine will serve as a working standard and will be included in all potency tests. The NRA approves the reference preparation used and the potency limits applied. The performance of this reference vaccine should be monitored by trend analysis using relevant test parameters, and it should be replaced when necessary.