Washington  - A vaginal gel which can kill the HIV virus during sexual intercourse was hailed Monday for showing it was somewhat effective in preventing infection and for holding promise as another weapon in the arsenal against the deadly disease.

The gel, PRO2000 produced by Indevus Pharmaceuticals, was 30 per cent effective in reducing the incidence of AIDS during four years of trials in Africa and the United States, according to research revealed at an AIDS conference in Montreal, Canada.

"We think it's quite exciting," Lori Heise of the Washington-based Global Campaign for Microbicides, told Deutsche Presse-Agentur dpa.

She is director of an advocacy campaign for the needs of women in combatting HIV/AIDS, and was not directly involved in producing or testing the substance.

"What we have lacked in this field is what scientists call proof of concept," she said. "This trial clearly demonstrates that we can reduce risk through a vaginal product."

The tests on PRO2000 were carried out by the Microbicide Trials Network and funded by the US National Institutes of Health.

The study was conducted in South Africa, Malawi, Zambia, Zimbabwe and the United States, where 3,000 women tested the product.

Women who were given the PRO2000 gel and condoms had a 30 per cent lower infection rate than women given a fake gel and condoms and women who were only given condoms, according to press statements about the study.

It was not determined by researchers whether women used either the gel or the condom every time they had intercourse, or if they used no contraceptive at all. After about
20 months, their HIV infection rates were measured. (dpa)