Three conjugation methods for use with the capsular saccharide ofStreptococcus agalactiae. In the first method, reductive animation of oxidisedsialic acid residue side chains is used, but the aldehyde groups are firstaminated, and then the amine is coupled to a carrier via a linker. In thesecond method, sialic acid residues and/or N-acetyl-glucosamine residues arede-N-acetylated to give amine groups, and the amine groups are coupled to acarrier protein via a linker. In the third method, linkage is via galactoseresidues in the capsular saccharide rather than sialic acid residues, whichcan conveniently be achieved using galactose oxidase.
