A cancer vaccine consisting of a recombinant fowlpox virus encoding fragment of human prostate-specific antigen (PSA), PSA:154-163 (155L), and a TRIad of COstimulatory Molecules (B7-1, ICAM-1 and LFA-3) (TRICOM). Administration of this agent may induce a cytotoxic T cell response against PSA-expressing tumor cells. Dendritic cells infected with TRICOM vectors greatly enhance naive T-cell activation and peptide-specific T-cell stimulation. Fowlpox virus is an attractive vector because its genome is easy to manipulate and it is replication incompetent in mammalian cells.