WHATʼS NEW?: Cancer vaccines using genetically-engineered viruses have not been as successful as originally hoped. In this study, the authors asked whether first priming the immune system with antigen alone might improve the success of a viral vector. Melanoma patients were given priming injections of an antigen called NY-ESO-1 plus ISCOMATRIX adjuvant. Several patients who then received injections of a fowlpox virus encoding NY-ESO-1 had improved CD8+ T-cell responses, compared to no improvement in patients who simply received more of the isolated antigen.