Method for quantification of polysaccharide content in conjugate vaccines

A method for identification and/or quantification of a polysaccharide serotype present in a vaccine drug product, said method comprising the steps:

• a) obtaining a standard sample comprising a polysaccharide serotype corresponding to a serotype present in the vaccine drug product;
• b) obtaining a vaccine drug product sample stock solution that was prepared from the vaccine drug product;
• c) adding to the vaccine drug product sample stock solution, a serospecific anti-polysaccharide antibody corresponding to the polysaccharide serotype of step (a) creating a mixture, wherein the amount of serospecific anti-polysaccharide antibody added is sufficient to ensure that all antibody binding sites on the polysaccharide serotype in the vaccine drug product stock solution are occupied by the corresponding serospecific anti-polysaccharide antibody, to form an antibody-polysaccharide complex (APC) in the mixture;
• d) subjecting the APC in the mixture to a chromatographic separation method to provide a quantitative peak area;
• and
• e) using a linear fit equation to calculate the amount of the free polysaccharide of the serotype used in step (a) that is present in the mixture, wherein the linear fit equation takes into account the slope and intercept of a standard curve for the polysaccharide serotype corresponding to the polysaccharide serotype of step (a) along with the quantitative peak area generated in step (d);
• and
• f) optionally repeating steps (a) through (e) one or more times to identify and/or quantify other polysaccharide serotypes that are present in the vaccine drug product.