An immunogenic composition comprising a fusion protein-polysaccharide conjugate consisting of a polysaccharide (PS) or pneumococcal bacterial cell wall polysaccharide (CWPS) conjugated to X:PdT where PdT represents the nonhemolytic variant of pneumolysin and X represents an antigenic peptide or protein of interest is provided. The immunity to X is synergistically enhanced by the fusion conjugate. Methods of protecting a subject from pneumococcal colonization or disease by administering an immunogenic composition including a fusion protein (PsaA:PdT) containing truncated PsaA and the nonhemolytic variant of pneumolysin (PdT) conjugated with CWPS (PsaA:PdT-CWPS) is also provided.