Polysaccharide and glycoconjugate vaccines

Polysaccharide and protein glycoconjugate vaccines combine adjuvants with high-molecular-weight polysaccharide antigens, typically including several serotypes. In protein glycoconjugates, protein adjuvants are covalently linked directly to the polysaccharide.

Since molecular weight is central to the immunogenicity of this type of vaccine, SEC-MALS and FFF-MALS are essential for their characterization and quality control.

Size and molar mass characterization

FFF‐MALS, combining an Eclipse FFF controller, DAWN MALS detector, Optilab™ dRI detector and industry-standard HPLC components, is the preferred means of characterizing protein-polysaccharide conjugate vaccines that extend above tens or hundreds of MDa in MW. As there is no column matrix, there is no shear‐induced degradation while fractionating the entire range; MALS determines molar mass and size simultaneously.

For smaller molecules, SEC-MALS may be more readily utilized. Typically, SEC-MALS can determine not only the overall molar mass of the molecule, but also quantify the content of protein and content of polysaccharide in each eluting fraction. A SEC-MALS system includes HPLC pump, autosampler and column, a DAWN and Optilab, and may also include a ViscoStar™ differential viscometer for additional analysis of conformation.