Peptide vaccines against cancer, infectious diseases, and conception.

The concept of peptide vaccines is based on identification and chemical synthesis of B-cell and T-cell epitopes which are immunodominant and can induce specific immune responses. B-cell epitope of a target molecule can be coupled to a promiscuous T-cell epitope to make it immunogenic. Our increased understanding of antigen recognition at molecular level has resulted in the development of rationally designed peptide vaccines. The relative ease of construction and production, chemical stability, and lack of oncogenic or infectious potential has made the peptides attractive vaccine candidates. However, several obstacles limit the widespread usefulness of peptide vaccines. These include their low immunogenicity, need for a better adjuvant and carrier, and reliable and simple assays to measure T-cell response. Nonetheless, current efforts are defying these limitations and many promising discoveries are making their way to improve this approach. The peptide vaccines against various cancers have undergone phase I and phase II clinical trials with successful immunological clinical outcome. The peptide vaccination is being examined both for palliative and prophylactic immunotherapy. The current status of many peptide vaccines which are being developed against cancer, infectious diseases, and conception is discussed in this review.