The present application discloses a method for making an immunogenic composition comprising an improved way of conducting saccharide-protein conjugation reactions using carbodiimide condensation chemistry. Depending on the nature of the saccharide or protein carrier involved, the quality of the conjugate may be improved by adding one of the reaction components slowly to the reaction mixture. In addition, the conjugate is mixed with a staphylococcal antigen. Immunogenic compositions are further provided comprising the saccharide-protein conjugates made by the methods disclosed.
