An immunogenic conjugate comprising a peptide immunogen covalently attached to a carrier protein, wherein the immunogenic conjugate has the formula: wherein, C is a carrier protein selected from the group consisting of CRM197, Streptococcus pyogenes ORF1224, Streptococcus pyogenes ORF1664, Streptococcus pyogenes ORF2452, and Chlamydia pneumoniae ORF T858, Xd is a derivatized functional group of an amino acid residue of the carrier protein. P is a peptide immunogen comprising an Aß fragment covalently attached to the derivatized functional group of the amino acid residue of the carrier protein R is a capping molecule covalently attached to the derivatized functional group of an amino acid residue of the carrier protein, whereby the functionality of the carrier protein is preserved, such that it retains its ability to elicit the desired immune responses against the peptide immunogen that would otherwise not occur without a carrier, n is an integer greater than 0, but less than or equal to 38, and p is an integer greater than 0, but less than or equal to 38.
