(184b) Polysaccharide Charge Reduction For Conjugation Vaccine Modernization

A lower charge ratio of polysaccharide to protein was investigated as part of modernizing the process for a conjugate vaccine. Historical data indicates that the polysaccharide is not fully consumed in the conjugation reaction. By modifying the amount of polysaccharide charged, we optimized reaction efficiency and enabled a cost savings by improving yields. These experiments also led to an improved understanding of reaction kinetics, which had been previously limited by analytical capabilities. Initial experiments explored the limits of the polysaccharide to protein ratio and mapped reaction kinetics. A thirty-two arm design of experiments further investigated these two factors and supported the polysaccharide charge optimization with no impact to product critical quality attributes. Future studies will explore a broader range of polysaccharide charge ratio to further define optimized and robust conjugation.