Prostate cancer vaccine research. Researcher working in a laboratory developing a vaccine for prostate cancer. He is developing a vaccine that will stimulate the body's immune system to attack cancer cells. The vaccine consists of inactivated cancer cells from 3 different stages of the disease. It is hoped the introduction of these cells will prime the immune system to mount a more effective attack on the body's own prostate cancer cells. The prostate is a small gland found just below the bladder surrounding the urethra, the tube urine passes through. The causes of prostate cancer are not known, but it is most prevalent in men over 50 years of age. The vaccine is being developed by Onyvax Ltd, St George's Hospital Medical School, London, UK.