HIV gel breakthrough

A study has found that a new vaginal gel called Pro2000 reduces the odds of HIV infection by 30 percent in women, says the Medical Research Council (MRC).

"For the first time since the epidemic we are seeing something that would provide an option for women to prevent infection," principal investigator Professor Gita Ramjee told journalists at the council's branch in Chatsworth.

The results of the study were also presented at an international meeting in Montreal, Canada on Monday.

The study, involving 3 099 women, was conducted between February 2005 and September 2008 in Malawi, South Africa, Zambia, Zimbabwe and the United States.

Ramjee said two products were tested - Pro2000 and BufferGel.

During the course of the study, 194 infections occurred – 36 infections among women using Pro2000, 54 infections occurred among women using BufferGel, 51 infections occurred among participants who were given a placebo gel, while 53 infections occurred among participants who used no gel.

Promising findings
"The trial found that women who were offered PRO2000 gel plus condoms had 30 percent fewer HIV infections than those offered only condoms or condoms plus a placebo gel," said the Global Campaign for Microbicides (GCM) in a press release.

In another analysis that accounted for the time that women did not use the products because they were pregnant, the study found PRO2000 to be 36% protective against HIV compared to the control arms. The other candidate microbicide tested, BufferGel, did not reduce HIV risk among women.

"The results on PRO2000 are a ray of hope for women," observed Lori Heise, Director of GCM, an advocacy organisation that has been campaigning to expand women's HIV prevention options for over a decade. "This is the first time that we have had human data actually showing that a vaginal gel can work to reduce infection. It's not a home run, but this "proof of concept" should invigorate the field."

Another effectiveness trial of PRO2000, conducted by the UK-funded Microbicide Development Programme (MDP), is currently in its final stages in South Africa, Tanzania, Uganda and Zambia. This trial—known as MDP 301-has enrolled over 9 000 women, three times the number enrolled in the current trial.

"This second trial should help us refine our estimate of how effective PRO2000 actually is," noted Dr Samu Dube, GCM's Africa Program Leader. With three times the number of women, the MDP trial will yield an even more precise estimate of effectiveness. We will need such data before deciding whether it makes sense to move this product forward toward licensing and distribution."

Much remains to be done
"Much remains to be done before we will have a viable product to distribute," notes Dube, "But as an African woman, a physician, and a mother, my message is that this is a great day for women and for prevention research."

Microbicides are substances designed to prevent or reduce the transmission of HIV or other sexually transmitted infections.

Ramjee said the outcome of the study showed there was hope. "After working for over a decade in microbicide research, we are seeing a glimmer of hope of finding a safe and effective microbicide which could protect women and substantially reduce new HIV infections here in South Africa and globally."

Although no microbicides are approved or available for use, an effective product could provide women with an HIV prevention method which they can initiate, she said.

"This would be particularly helpful in situations where it is difficult or impossible for women to negotiate condom use with their male partners."

Women account for half of the 33 million people living with HIV/Aids worldwide. In sub-Saharan Africa, women account for 60 percent of all infected adults.

In several southern African countries, young women between the age of 15 and 24 are at least three times more likely than their male peers to be infected with HIV.

(Sapa/Health24, February 2009)