A vaginal microbicidal
gel containing the antiretroviral drug tenofovir (Viread) reduced the risk of HIV infection among women who received
it by 39% during a two-and-a-half-year study in South Africa, the Eighteenth
International AIDS Conference will hear tomorrow.
Go to the following day's presentation and report
used it during at least four out of five sex acts had an even greater reduction
in their risk of becoming infected (54% reduction), and the gel halved women’s
risk of acquiring HSV-2, the virus that cause genital herpes. HSV-2 also
increases the risk of HIV acquisition.
The results of this study have reinvigorated the field Professor Sharon Hillier, principal
investigator of the Microbicide Trials Network
recruited 889 sexually active women in Kwazulu Natal province
in South Africa,
and randomised them to receive either a microbicide gel containing 1% tenofovir or a gel containing a placebo. Neither the women nor the trial investigators knew whether they were receiving the tenofovir gel during the study.
known as CAPRISA 004, was conducted by Dr.
Salim Abdool Karim of the Centre for the AIDS Programme of Research in South
of the study had been kept under tight wraps, but the Financial Times broke the embargo early this evening.
results of the study will be presented at 1pm Central European Time tomorrow,
but ahead of the presentation international bodies and agencies leading the
microbicide research agenda welcomed the development.
“This study has established proof of concept that a vaginal
microbicide containing an ARV can protect women from HIV. This is an incredibly
important achievement for which the CAPRISA team is to be congratulated. For
all of us in the HIV prevention field, this result has shown that it may be
possible to leverage this initial success using a single ARV at the time of sex
into more potent approaches that could be 50, 60 or even 70% effective
for prevention of HIV. The results of this study have reinvigorated the field,”
commented Professor Sharon Hillier, director of reproductive infectious disease
research at the University of Pittsburgh School of Medicine, and principal
investigator of the Microbicide Trials Network (MTN).
“These efficacy results are
statistically significant and should be celebrated,” said Dr Zeda Rosenberg of
the International Partnership for Microbicides, in reference to results of a previous microbicide study (HPTN
035) of another product, PRO 2000, that briefly excited the field. That
study showed a result of borderline significance, and a subsequent, larger
study, MDP 301, failed to
reproduce the result.
is an important day,” said Yasmin Halima, director of the Global Campaign for
Microbicides. “We now have evidence that a vaginal gel can help prevent
HIV. This is good news for women, good news for the field, and a good day for science.” “Today’s
news energises the field,” Halima said. “We hope it urges others to support the
expansion of programs for developing topical HIV-prevention products."
To stimulate and prioritise rapid action, WHO and UNAIDS announced tonight
that they will convene an expert consultation in August with women’s health and
HIV prevention advocates, scientists, microbicide research teams and product
developers, and public health experts to discuss the next steps with the