Patent ID: 7955605

Claim:
A method for making an immunogenic conjugate comprising Streptococcus pneumoniae serotype 19A polysaccharide covalently linked to a carrier protein, the method comprising: (a) reacting purified serotype 19A polysaccharide with an oxidizing agent resulting in an activated serotype 19A polysaccharide; (b) compounding the activated serotype 19A polysaccharide with a carrier protein; (c) co-lyophilizing the compounded activated serotype 19A polysaccharide and carrier protein; (d) re-suspending the compounded activated serotype 19A polysaccharide and carrier protein in dimethyl sulfoxide (DMSO): (e) reacting the compounded, activated serotype 19A polysaccharide and carrier protein with a reducing agent resulting in a serotype 19A polysaccharide:carrier protein conjugate; and (f) capping unreacted aldehydes in the serotype 19A polysaccharide:carrier protein conjugate resulting in an immunogenic conjugate comprising Streptococcus pneumoniae serotype 19A polysaccharide covalently linked to a carrier protein; wherein step (c) is performed after step (b) and before steps (d) and (e).