Patent ID: 8790893

Claim:
A method for preparing a vaccine composition, comprising the steps of: (a) providing a capsular saccharide whose degree of polymerization (DP) has been measured by a process comprising the steps of: (i) reducing the terminal sialic acid monosaccharide subunit to give a reduced sialic acid monosaccharide subunit; (ii) hydrolyzing the saccharide to give a hydrolysate containing monosaccharide subunits, wherein the hydrolysis proceeds to completion to yield only monosaccharide subunits; and (iii) determining the ratio of total sialic acid to reduced sialic acid in the hydrolysate, wherein the capsular saccharide comprises sialic acid monosaccharide subunits that are linked α 2→9 and has a terminal sialic acid monosaccharide subunit; (b) conjugating the DP-analyzed capsular saccharide to one or more carrier proteins; (c) analyzing the bulk vaccine comprising the conjugated capsular saccharide for pH and/or other properties; and, if the results from step (c) indicate that the bulk vaccine is acceptable for clinical use, (d) preparing and packaging the vaccine for human use from the bulk vaccine.