US Patent 11992521 Methods for producing

A method is described for producing a pneumococcal capsular polysaccharide protein conjugate in which one or more activated pneumococcal polysaccharides of particular pneumococcal serotypes and carrier protein are separately lyophilized, the separately lyophilized polysaccharides and carrier protein are separately reconstituted in an organic solvent, and the reconstituted polysaccharide and carrier protein are then combined together by Tee-mixing and conjugated together to produce polysaccharide carrier protein conjugates. A plurality of conjugates, each comprising polysaccharides of a particular serotype, may be used to produce multivalent pneumococcal immunogenic compositions having a combination of conjugates for use in vaccines.