After years of disappointments, South African Aids researchers have announced results from a trial in which a vaginal microbicide appeared to offer promise in preventing HIV infection in women.
According to findings from a clinical trial involving more than 3 000 women in Malawi, South Africa, Zambia, Zimbabwe and the US, the microbicide PRO 2000 gel was 30% effective.
“This is the first time in the history of microbicide research that we have found something that works, even if its 30%,” Gita Ramjee, principal investigator of the trials in South Africa, told journalists on 9 February in the country’s east coast port city of Durban.
Ramjee described the results as a “glimmer of hope” that the microbicides concept could become an effective HIV prevention tool for women.
Women in the trial were randomly assigned to one of four groups: one group involved women who received a 0.5% dosage of PRO 2000 gel; in the second, women were treated with BufferGel, a second microbicide candidate; and in the third and fourth groups women received a placebo gel or no gel at all
The study, conducted by the US-based Microbicide Trials Network, also found more that regular gel use corresponded to a higher level of HIV protection.
According to Ramjee, PRO 2000 provided protection of up to 78% against the virus in women who were not able to negotiate condom use, but reported more frequent application of the gel. The study also reported a higher level of adherence: participants in the three gel groups reported using the gel 81% of the time.
Results from a larger study of PRO 2000 are expected later this year and it is hoped it will be able to demonstrate efficacy if they find similar reductions in the HIV infection rate.
Trial participant Desiree, who declined to use her last name, was not sure of what to make of the hype surrounding the results of the clinical trials.
“One on one side I am proud of what I did and I am quite glad there is some progress, but I don’t want to get too excited just in case it doesn’t work in the end,” the 26-year old mother said.
“Some people felt because I was Indian I shouldn’t do it, but I didn’t listen to them. But my mother was fine, she said ‘OK no problem’, and my partner was also fine. We even enjoyed using the gel,” she said.
The South African arm of the trials was conducted in Durban’s traditionally Indian township of Chatsworth, as well as the rural district of Hlabisa in northern KwaZulu-Natal.
Dr Samu Dube, the Africa programme Leader for the Global Campaign for Microbicides, has cautiously welcomed the findings.
“It is the first time we are seeing positive news on clinical trials [of microbicides], it is a smiling moment. But we expect more. For us to jump around, the results should be statistically significant. But we will get there,” she said.
The microbicide field has been desperate for positive news after a host of depressing trial results, which included the 2007, clinical trials – using a cellulose sulphate-based microbicide – which were terminated after preliminary findings found higher HIV infections in the trial group compared to the placebo group.
In 2008, the US-based reproductive health organisation, Population Council announced that Carraguard – the first microbicide to complete the advanced stage of clinical testing – had also failed to prevent HIV infection.
In a statement, Lori Heise, director of the Global Campaign for Microbicides, said PRO 2000 was “not a home run, but this proof of concept should “invigorate the field.”
Although the results were “promising” they are not statistically significant, as there was a one-in-ten chance that the 30% reduction in HIV infections seen in women who used PRO 2000, versus those who used a placebo, was due to chance, Ramjee explained
Scientifically, results are not regarded as “significant” unless the chance they are wrong is 0.05% or less than one in 20. “If we had seen a 33% reduction it would have been statistically significant,” Ramjee said.
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- Source: Irin PlusNews