Side effects can be very severe, although in one study the overall quality of life was reported to be better for those who took interferon than for those who did not. A similar drug, interferon alpha 2a, is also showing promise and may even be beneficial for Stage II patients. The drug has very severe side effects, including very low blood pressure, heart rhythm abnormalities, severe infections, and shortness of breath, but they are manageable and nearly always reversible. Unlike chemotherapy, in which the drugs directly attack the tumor and shrinkage occurs quickly, the use of vaccines requires the body to build up its own defenses. It can take months before beneficial effects occur, but when they do, tumor reduction is much more lasting than with chemotherapy.
Vaccines also seem to have fewer side effects than interleukin and interferon.
Autologous vaccines are made from the patient's own cancer cells or parts of them. One problem with this approach is that there is no way to scientifically assess outcome or even guarantee repeated success since each vaccine is unique to the individual patient. One such vaccine called CancerVax is showing promise in certain patients. Opponents to the allogeneic approach argue that there may be an increased risk for eventual tumor resistance to such antigens. A relatively new technique that may benefit patients with stage IV melanoma is cytoreductive surgery plus adjuvant immunotherapy.