Therapeutic vaccines for melanoma: progress and problems.

Melanoma vaccines, which have been under development for many years, are being refined as a result of the knowledge gained from practical testing. We now have a more complete understanding of their mode of action and the problems that remain to be solved. There are points to recommend both crude and pure vaccines-each have specific advantages, but both require further development. Isolation of relevant peptide epitopes, addition of co-stimulatory molecules, the development of novel vehicles for vaccine delivery and improved vaccine adjuvants, and the problem of tumor-induced immunosuppression are among the issues for future study.