Vaccination is a major means of combating infectious disease but no effective vaccine is available yet for many parasitic, viral and bacterial infections. A new approach consists of vaccines based on synthetic peptides rather than native parent antigens. The contributors to this symposium discuss the antigenicity and immunogenicity of synthetic peptides and their potential use in vaccines against malaria and other serious diseases. They consider the relationship between protein conformation and antigenicity, including the role of localized mobility and the conformational changes induced when peptides bind with immunoglobulin. A new method of synthesizing peptides able to mimic discontinuous epitopes is described. The symposium opens with a review of the regulation of immune responses in vivo. Carrier molecules such as PPD are being investigated; carrier choice plays a crucial role in the anti-hCG vaccine (based on a synthetic peptide) being tested as a means of birth control, and discussed here.
Synthetic peptides are also of use as research tools, as described for the analysis of IgG sites responsible for autoantibody production in rheumatoid arthritis, and the localization of the c-myc oncoprotein in normal and transformed cells and in tumour masses.