An experimental vaginal gel has yielded promising results in preventing HIV infection in women, according to clinical trials conducted in Africa and the United States, the US National Institutes of Health said Monday.
The microbicide PRO 2000 made by Lexington, Massachusetts-based Indevus Pharmaceuticals, Inc., proved safe and 30 percent effective in preventing AIDS infection, the NIH said.
Thirty-three percent effectiveness would have been considered statistically significant, it added.
"Although more data are needed to conclusively determine whether PRO 2000 protects women from HIV infection, the results of this study are encouraging," said National Institute of Allergy and Infectious Diseases (NIAID) director Anthony Fauci in a statement.
The NIH's first large clinical study of a microbicide, involving more than 3,099 women in six African cities and one in the United States, was the first to suggest that a microbicide gel applied topically to the vagina or rectum may prevent male-to-female sexual transmission of HIV infection, the institutes said.
The results of the clinical trials were presented Monday by NIH at the Conference on Retroviruses and Opportunistic Infections in Montreal, Canada, the NIH said. NIAID is part of the NIH.
"An effective microbicide would be a valuable tool that women could use to protect themselves against HIV and one that could substantially reduce the number of new HIV infections worldwide," Fauci said.
"The study, while not conclusive, provides a glimmer of hope to millions of women at risk for HIV, especially young women in Africa," said Salim Abdool Karim, lead investigator in the NIH-funded study and researcher from the Center for the AIDS Program of Research in South Africa.
"It provides the first signal that a microbicide gel may be able to protect women from HIV infection," he added.
Women make up 50 percent of all HIV-infected people worldwide, but nearly 60 percent in sub-Saharan Africa, NIH said.