This could be a turning point in the battle against HIV, particularly in Africa where 60 per cent of new infections are in women. New Scientist explores why
What is this gel, and how is it used?
It contains the anti-retroviral drug tenofovir. Women squirt the gel into their vagina using a special applicator 12 hours before sex, and 12 hours after.
How well did it work?
In the trial in South Africa, the 445 women receiving the active gel were 39 per cent less likely to become infected with HIV than the 444 using a placebo gel. Among women who used the gel exactly as instructed, the infection rate fell by 54 per cent, suggesting that rates could be halved if women use it properly.
Were there any other benefits?
Infection rates also halved for herpes simplex virus 2, which makes infection with HIV more likely.
Is it possible that women taking part in the trial were less safety-conscious than usual because they thought the gel would protect them?
Unlikely. The researchers say they explained fully to all participants that some would receive an ineffective treatment. Also, they provided participants with condoms and stressed the importance of carrying on with all existing methods of avoiding infection.
Who did the trial?
It was organised by the Centre for the AIDS Programme of Research in South Africa (CAPRISA), run by the University of KwaZulu-Natal in Durban, with collaborators in the US and funding from the US Agency for International Development and the South African government. The lead researchers were Salim Abdool Karim of the University of KwaZulu-Natal and his wife, Quarraisha Abdool Karim of Columbia University in New York.
Why is the result so significant?
It has succeeded where six other gels have failed in a total of 11 trials since 2004. In one trial infection rates actually increased, leading to doubts whether gels would ever work.
With the potential to halve HIV infection rates, the new gel could massively dent the AIDS epidemic, especially in Africa where rates are highest. Quarraisha Karim told a press conference on 19 July that even at the lower rates of protection, if one-third of South African women used the gel it could prevent 1.3 million infections and 820,000 deaths over 20 years.
Why did this gel work where others failed?
Primarily because it contains the anti-retroviral drug tenofovir. Salim Karim says that all previous gels worked purely as barriers on the surface of the vagina, whereas the new gel penetrates and protect from within the cells that HIV normally infects.
Why is it especially important for women?
Because they have so little to protect themselves with otherwise, especially in situations where men may be unwilling to wear condoms. With access to the gel, women can make their own decisions about whether to protect themselves.
Could this help reduce the spread of HIV and AIDS?
Yes, especially coupled with the fact that in men circumcision reduces infection rates by 60 per cent, and mother-to-child transmission of HIV can be roughly halved by giving pregnant women the anti-retroviral drug nevirapine. The gel could help close down another significant avenue of infection in Africa.
How soon will the gel be available commercially?
The researchers say that another trial is needed to confirm the results, and to refine the formulation so it works even better. Because the initial results are so encouraging, UNAIDS (the Joint United Nations Programme on HIV/AIDS) and the World Health Organization are holding a meeting next month to try and fast-track approval.
Who will make the gel?
Gilead, the California-based company which developed tenofovir, has granted the South African government permission to make the drug and to sell it in the gel without having to pay the company a royalty. The gel will still have to be licensed and approved for sale in individual countries, which could take two years or more.
What are people saying about the results?
"We are giving hope to women," says Michel Sidibé, executive director of UNAIDS. "For the first time we have seen results for a women-initiated and controlled HIV prevention option."
Patrick Kiser of the University of Utah, who is developing an anti-HIV gel that doubles as a contraceptive, says: "We are all very excited about the breakthrough and I congratulate the trial participants and investigators. The results usher in a new and exciting era of products that can be used by women to protect themselves from HIV and other sexually transmitted infections in the developing and developed worlds."
Journal reference: Science, DOI: 10.1126/science.1193748
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Vivagel
Thu Jul 22 02:46:05 BST 2010 by Andos
There is a possibly more promising vaginal gel currently in development by an Australian company, Starpharma, called VivaGel.
This gel is based on dendrimers and has demonstrated effective inhibition of HIV and HSV-2 even 24 hours after application (see http://www.asx.com.au/asxpdf/20090803/pdf/31jx7p9nrjcv4j.pdf ).
VivaGel is still undergoing clinical trials, but it promises to be a huge factor in the fight against the spread of HIV, and could cut the HIV infection rate even more than the gel mentioned in this article.
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2010-07-27
Vaginal gel could slow spread of HIV - health - 21 July 2010 - New Scientist
via newscientist.com
