Gel scores in HIV fight

21 July 2010 - 01:34 By Claire Keeton

The new anti-retroviral-based gel safely reduces by 39% the risk of women getting HIV during sex, scientists told delegates at the International Aids Conference in Vienna, Austria, yesterday.

Moreover, its efficacy rose to 54% among the group of women who followed instructions on how to use it for 80% or more of their sex acts.

A gel like this has the potential to prevent one new infection for every 20 women exposed to HIV, and one new herpes infection for every seven women at risk of HSV-2.

Professor Salim Abdool Karim, the principal co-investigator and director of the Centre for the Aids Programme of Research in South Africa (Caprisa), said: "We have the potential to prevent 1.3million new infections among women over the next two decades in South Africa."

An added bonus is that the microbicide cut by 51% the risk of genital herpes (HSV-2), which is common among people with HIV.

Karim said: "We were stunned in disbelief. We didn't speak for nearly a minute when we got the results. We are talking about 39% protection versus zero. There is no alternative for women."

The result is particularly significant because vaginal microbicides are the first and only HIV prevention tool that women can control.

Professor Malegapuru Makgoba, vice-chancellor of the University of KwaZulu-Natal, said in a statement: "This piece of research is a significant milestone for women in the 30 year history of the HIV/Aids epidemic, microbicides and antiretroviral research.

". These research findings will not only significantly alter the shape and form, but also the future direction, of this devastating epidemic."

About two-thirds (68%) of the female volunteers did tell their partners they were testing the tenofovir microbicide, which is clear, odourless and viscous. More than half of these male partners had no reaction to it, and many said they did "not feel anything".

"Tenofovir gel can potentially fill an important HIV gap, especially for women unable to successfully negotiate mutual monogamy or condom use," the scientists, led by husband and wife team, Dr Quarraisha Abdool Karim and Professor Salim Abdool Karim, reported in the journal, Science.

The female volunteers showed no increase in HIV risky behaviour while using the gel. One of them, Xoliswa Mthethwa, 20, said the trial was unproblematic from "beginning to the end".

Asked if she would buy a product like this if it worked, she said: "I would be number one in the queue to go and buy it."

Until now the only HIV prevention methods proven to work in scientific trials are:

  • Male circumcision, which offers men 57% protection and has been tested in three trials;
  • The treatment of sexually transmitted diseases, which lowers HIV risk by 42%, but this result has not been confirmed; and
  • A partially effective vaccine tested in Thailand, which offers 31% protection.

Out of 37 random controlled HIV prevention trials, there have been only five successful interventions, said Quarraisha Abdool Karim.

Over the past 15 years, six microbicide candidates were tested in 11 of the 37 trials and none of them proved to be even partly effective.

But the Caprisa study marks a turning point, and proves that an antiretroviral-based gel has potential to block HIV.

She said the World Health Organisation was helping to map out the way forward among role players in the field.

Reverend Paul Sithole, chairman of the research support group in Vulindlela, said the female volunteers were the "real heroes of this project".

"If the result was negative we would be crying like the Netherlands, but now we are rejoicing like Spain," he said, referring to the World Cup Soccer finalists.

The local chief, Inkosi Sondela Zondi, said he was excited about the results coming out of his community - 611 of the 889 volunteers were from the rural site.

"It is hard to be the leader of a dying nation . [now] there is light at the end of the tunnel."

Zondi worked with other community leaders to dispel the lie that the gel was causing HIV.

"No nkosi would give up his people to be killed," he said, adding that he supports using such a gel within his own family.