WHO/BS/2015.2255.Add.1 Evaluation of candidate IS for Meningococcal Serogroups A and X polysaccharide

Overview

This report outlines the collaborative study and in-house evaluation at NIBSC of two candidate International Standard preparations: meningococcal serogroup A (MenA) and serogroup X (MenX) polysaccharides. Plain polysaccharide (PS) and conjugate vaccines are primarily evaluated by physicochemical methods to ensure that batches are consistently manufactured. As different assays are employed to quantify the PS content of final formulations and bulk intermediates, there is a need for International MenA and MenX PS Standards to calibrate internal references used in the different laboratories. Eleven laboratories from nine different countries participated in the collaborative study to assess the suitability of candidate International Standard MenA and MenX PS preparations (coded 13/246 and 14/156).