Researchers stop
studies of AIDS prevention gels

Researchers have halted two studies of a vaginal microbicide in Africa and India that doctors had hoped would prevent HIV infection, after results suggested the gel might raise rather than lower that risk.

The results are ''a disappointing and unexpected setback'' to efforts to get a simple tool that women could use to lower their risk of getting the AIDS virus from sex, said a statement from the World Health Organization.

The large final-stage experiments were in parts of Africa and India. More than half of all new infections with the AIDS virus in Africa involve women and girls, and scientists have long sought a method they could use, even without their partners' knowledge, to reduce risk, because many men refuse to use condoms.

The studies were testing Ushercell, a gel containing cellulose sulfate, a cotton-based compound developed by Polydex Pharmaceuticals based in Toronto.

One study involving 1,500 women in South Africa, Benin, Uganda, and India was stopped this week after an independent safety monitoring board saw more HIV infections among women using the gel than those given a dummy medication. The study was led by CONRAD, a Virginia-based health research group, and paid for by the U.S. Agency for International Development and the Bill and Melinda Gates Foundation.

The second study of Ushercell, by Family Health International, involving 1,700 women in Nigeria, was stopped as a precaution although no increased risk of infection has been seen. (Marilynn Marchione, AP)