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)