This invention relates to a process for preparing a hapten-protein-polysaccharide conjugate and a hapten-protein conjugate by reacting a protein with a hapten to produce a hapten-protein conjugate, followed by reacting the hapten-protein conjugate with a polysaccharide to provide a conjugate mixture including the hapten-protein conjugate and a hapten-protein-polysaccharide conjugate. This invention also includes the process described above with the addition of a pharmaceutically acceptable medium or delivery vehicle into the conjugate mixture. The invention further includes the process described above where the hapten is luteinizing hormone releasing hormone peptides derived from E coil, or malaria derived peptides.