Microbicides - substances that scientists had believed could reduce transmission of the HIV/Aids virus in women may not come that soon, a senior official from the partnership that is developing the substances said on Thursday.

Dr Zeda Rosenberg - Chief Executive Officer of the International Partnership for Microbicides - IPM - said in Kigali that despite the grim figures showing that women are most at risk of infection, studies on numerous Microbicides are not making head way.

Microbicides are substances that are designed, when applied vaginally, to reduce transmission of HIV or other sexually transmitted infections (STIs). Some microbicides under development also function as spermicides to provide contraceptive protection. Eventually, microbicides are likely to be available as gels, creams, films, suppositories, or vaginal rings.

"Clinical trials have not turned out the way we hope they should", Dr Rosenberg told a stakeholders symposium on HIV/Aids research. "We have not had any trials that we feel are working."

Dr Rosenberg said African women are more at risk because the "face of HIV is increasingly" female, targeting the young, mothers and in even monogamous marriages.

UN statistics show that last year, some 33.2 million people were living with the virus with more than 50% as women. Only on the African continent, is where women are counting for most of the infections. In Rwanda, out of the more than 250.000 HIV positive people, 64% are women.

With the development of vaginal microbicides, scientists say women would have a female-controlled method of protecting themselves from sexually transmitted infections.

Researchers have pointed out that a less effective microbicide used more often could actually provide more protection than a more effective product - such as condoms - used less often. Analysts have also noted, for example, that a method that is 30 percent efficacious yet used 60 percent of the time would provide more protection than a method that is 90 percent efficacious used only 20 percent of the time.

The substances are being developed on the premise that the microbicides are ideally safe, effective, low cost and user-friendly for the millions of prospective women beneficiaries, the senior executive said.

Five studies on different Microbicide types have been completed since 2000 in Cote d'Ivoire, Benin, Thailand, South Africa Ghana, Nigeria, Zimbabwe, Uganda and Zambia. But incidentally none does seem to have worked out as expected.

Research on the vaginal gel - which women would be able to apply into the vagina before having sexual intercourse was halted in Uganda last year. Scientists said they had found that the gel was not actually helping the case study women. They were being infected after using the cellulose sulphate gel.

In Rwanda, Dapivirine gel was on study between 2005 with results released in April last year indicating that the gel was "safe and well tolerated" in HIV-negative women, according to Dr. Joseph Vyankandondera of Projet Ubuzima.

Dapivirine gel trails were also done in Tanzania and South Africa. However, it also had several side effects.

"As of now, am afraid to say they (Microbicides) not yet available", said Dr Rosenberg of the International Partnership for Microbicides. The studies, according to her have been done "as ethically as possible" but "we have a long way to go".

She said no infections have been recorded during testing studies but there have always been risks that it does turn out wrong.

In the two-day session that started yesterday, the Rwanda National Aids Control Commission (NACC) is unveiling different research on HIV/AIDS as part of its Fourth annual conference on the scourge.

Lined on the program included clinical research and therapy, epidemiology and prevention, social and economic domain, policies and implementation of programs, regional survey and multi country programs on sociological research on HIV/AIDS.

More four trails are ongoing on different other Microbicides up until 2011. Next year, results from trails ongoing on BufferGel & PRO 2000 in Malawi, South Africa, Zambia, Zimbabwe and the United States will be out.