Anti-HIV gel 60-per-cent effective
Vaginal cream Microbicide protects women from virus
A prototype cream tested in South Africa reduced the risk of infection by the human immunodeficiency virus (HIV) by 39 per cent overall, but by 54 per cent among those women who used it most consistently, they said.
The report coincided with the six-day 18th International AIDS Conference, which opened in Vienna on Sunday.
The results must be validated in a third, wider phase in the arduous process of assessing a new medication for safety and effectiveness.
Although several questions have yet to be answered, the findings are a bright ray of hope in the 29-year campaign against acquired immunodeficiency syndrome (AIDS), the researchers said.
"Without this gel, we may see 10 women becoming infected in a year. With this gel, we would see only six women becoming infected," said Salim Abdool Karim, one of the two leading co-researchers, in a teleconference with reporters.
Twenty-five million people have died from AIDS and more than 33 million others are infected by HIV, which causes the disease.
More than two-thirds of these live in sub-Saharan Africa, where 60 per cent of new infections occur among women and girls.
One of the big vectors of transmission is through coercive intercourse by an infected partner who is unwilling to wear a condom.
The gel that was tested contains a one-per-cent formulation of tenofovir. It is a front-line component in the "cocktail" of antiretroviral drugs that disrupt HIV reproduction in immune cells.
Previous microbicides that have been tested have not contained an antiretroviral, and have had either a very low level of protection or even boosted the risk of infection.
Over nearly three years, the gel was tested on 445 HIV-negative women, while 444 counterparts received a harmless look-alike or placebo.
They were then tested for HIV at monthly followup visits, where they were also given counselling in safe sex, access to condoms and treatment for sexually-transmitted disease.
Each participant was asked to insert, using a vaginal applicator, a first dose of the gel within 12 hours before sex followed by a second dose as soon as possible but within 12 hours afterward.
The study, published by the U.S. journal, Science, was to be the focus of a seminar tomorrow at the world AIDS forum.
Availability of a microbicide that is 60-per-cent effective would avert two and a half million infections over three years, according to a 2003 mathematical study.