The invention is related to multivalent immunogenic compositions comprising more than one S. pneumoniae polysaccharide protein conjugates, wherein each of the conjugates comprises a polysaccharide from an S. pneumoniae serotype conjugated to a carrier protein, wherein the serotypes of S. pneumoniae are as defined herein. In some embodiments, at least one of the polysaccharide protein conjugates is formed by a conjugation reaction comprising an aprotic solvent. In further embodiments, each of the polysaccharide protein conjugates is formed by a conjugation reaction comprising an aprotic solvent. Also provided are methods for inducing a protective immune response in a human patient comprising administering the multivalent immunogenic compositions of the invention to the patient. The multivalent immunogenic compositions are useful for providing protection against S. pneumoniae infection and diseases caused by S. pneumoniae. The compositions of the invention are also useful as part of treatment regimes that provide complementary protection for patients that have been vaccinated with a multivalent vaccine indicated for the prevention of pneumococcal disease.
