Patent ID: 8895724

Claim:
A method for making an immunogenic conjugate comprising Streptococcus pneumoniae serotype 1 polysaccharide covalently linked to a carrier protein, the method comprising: (a) reacting purified serotype 1 polysaccharide with an alkaline pH buffer resulting in a partially de-O-acetylated serotype 1 polysaccharide; (b) reacting the partially de-O-acetylated serotype 1 polysaccharide with a mild acid resulting in a neutralized, partially de-O-acetylated serotype 1 polysaccharide; (c) reacting the neutralized, partially de-O-acetylated serotype 1 polysaccharide with an oxidizing agent resulting in an activated serotype 1 polysaccharide; (d) compounding the activated serotype 1 polysaccharide with a carrier protein; (e) reacting the compounded, activated serotype 1 polysaccharide and carrier protein with a reducing agent resulting in a serotype 1 polysaccharide:carrier protein conjugate; and (f) capping unreacted aldehydes in the serotype 1 polysaccharide:carrier protein conjugate resulting in an immunogenic conjugate comprising Streptococcus pneumoniae serotype 1 polysaccharide covalently linked to a carrier protein.