SAFETY COHORT: The first cohort of 3 patients receives vaccination with recombinant fowlpox-PSA vaccine intramuscularly (IM). Treatment repeats every 4 weeks for 3 courses. In the absence of unacceptable toxicity in the first cohort, the second cohort of 3 patients receives the same vaccine at the dose level immediately higher than the first cohort dose level. In the presence of unacceptable toxicity in the first cohort, the second cohort of 3 patients receives the same vaccine at a dose level lower than the first cohort dose level. The maximum tolerated dose (MTD) is the dose preceding that at which 1 of 6 patients experiences grade 3 or worse dose-limiting toxicity.