Circumcision reduces a man's chances of acquiring HIV by 60%, a new study finds. In a study of just over 3,000 South African men, researchers found such a marked different in HIV infection rates they had to stop the study on ethical grounds. Evidence appears to show that the virus attaches to foreskin cells. WHO: "If male circumcision is confirmed to be an effective intervention to reduce the risk of acquiring HIV, this will not mean that men will be prevented from becoming infected with HIV during sexual intercourse through circumcision alone. Nor does male circumcision provide protection for sexual partners against HIV infection."