Gilead Sciences Inc.'s Truvada pill in their lab in Foster City, Calif.
This Monday, May 26, 2006 file picture shows Gilead Sciences Inc.'s Truvada pill in their lab in Foster City, Calif. Two studies announced Wednesday, July 13, 2011 show the pill Truvada helped prevent the spread of the AIDS virus between heterosexual couples in Africa. The drug is already used to treat people with HIV. (AP Photo/Paul Sakuma)
Read the article: Studies show drug stops HIV among hetero couples