OBJECTIVES: I. Determine the effect of interferon alfa-2b on the potentiation of antimelanoma antibodies and cellular immune responses induced by immunization to a polyvalent melanoma vaccine and interleukin-2 in patients with stage III malignant melanoma. II. Determine the optimal dose of interferon that will maximally stimulate these responses in these patients. III. Determine the toxicity of this regimen in these patients.