Significant advances have been made in the field of peptide chemistry, especially in the design of synthetic peptide immunogens which has led to new concepts and strategies for human vaccine development. This article reviews some of these technological advances and approaches to vaccine design including the multiple antigenic peptide system, the lipid polylysine core peptide system, the polymerization of peptides into multivalent immunogens and self adjuvanting synthetic peptide-based immunogens.