The next step is to move on to studies that will confirm the compound works and to try to find doses that "are more applicable to the real world," Haase said.
There are other questions to be answered, including whether the treatment would protect men from infection when they have sex with men or women.
The good news: The compound would cost less than a cent for each dose for a woman, Schlievert said.
Dr. Jeffrey C. Laurence, a professor at Cornell University who studies AIDS, said the new study is innovative, because the treatment targets the body's immune responses rather than directly killing HIV itself.
The challenge is to develop a product that prevents AIDS and is also "unobtrusive, easy to use, and has long-lasting effects, so that it need not be applied daily or before each act of intercourse," said Laurence, who's also a senior scientist for programs at The Foundation for AIDS Research.
The U.S. Department of Health & Human Services has more about AIDS prevention drugs.
SOURCES: Ashley T. Haase, M.D., head, department of microbiology, and Patrick M. Schlievert, Ph.D., professor, biology, University of Minnesota, Minneapolis; Jeffrey C. Laurence, M.D., professor, Cornell University, and senior scientist, programs, The Foundation for AIDS Research, Ithaca, N.Y.; March 4, 2009, Nature, online
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