The gel offers moderate protection to women against HIV – reducing a woman’s risk of getting HIV during sex by 39%.
But among women with high adherence (80% or more) the efficacy was 54%.
It also provided 51% protection against genital herpes infections.
This is the first tool of HIV prevention that is within the control of women.
This is also the first positive result from a microbicide trial, after 11 trials testing six candidates in the past showed no effect.
It’s a day to celebrate since the results show prevention research is moving in the right direction.
Principal investigators, Dr Quarraisha Abdool Karim, Professor Salim Abdool Karim, their team and the 889 female volunteers, have given the microbicide field a major boost.
But the study, which is a proof of concept trial, needs to be repeated to scale to get independent confirmation of these results.
They are being presented at 1pm today at the XVIII International AIDS Conference in Vienna, Austria by the Centre for the AIDS Programme of Research in South Africa (CAPRISA).
Injecting drug users are not the only focus of the AIDS Conference in Vienna next week.
One of the priorities for African delegates will be the release of the results of the CAPRISA 004 microbicide trial next Tuesday, 20 July at 1pm.
This randomised controlled trial in South Africa tested the safety and efficacy of a 1% tenofovir-gel candidate, the first to use an antiretroviral to block infection.
The gel was tested among some 900 volunteers in CAPRISA’s rural Vulindlela site and urban Thekwini site.
Scientists and activists – particularly in the field of HIV prevention – are waiting in suspense to find out if this gel works.
None of the six candidates tested in 11 trials over the past 15 years has been successful yet.
The Global Campaign for Microbicides and Treatment Action Campaign have already organised a satellite session at the conference on the implications of the outcome.
The criminalisation of men who have sex with men is driving gay relationships underground in Africa and this discrimination is contributing to the spread of HIV on the continent.
The urgent need for access to health services for men who have sex with men, respect for their sexual orientation and protection in law, and lobbying for their human rights, emerged clearly at the M2010 Microbicides: Building Bridges in HIV Prevention conference in Pittsburgh, in the US, this week.
That was a key point in my article in the Sunday Times today – but I feel concerned that the headline “Secret gay sex fuels HIV spread in Africa” conveys a negative message.
What I feel negative about is the intolerable discrimination against men who have sex with men and how that isolates them from prevention, care and treatment.
As Michel Kazatchkine, executive director of the Global Fund to fight Aids, TB and Malaria, said in response to the recent imprisonment in Malawi of two men for having a gay relationship: “The criminalisation of individuals based on their sexual orientation is not just a human rights issue – it also … drives sexual behaviour underground and creates an environment where HIV can more easily spread.”
NOW that the M2010 Microbicides conference in Pittsburgh, in the US is over, the next big date on the microbicide and HIV prevention calendar is the 21 July 2010.
On that day the results of the first microbicide trial with a candidate using antiretrovirals will be announced at the XVIIIth International AIDS Conference in Vienna, Austria.
Professor Salim Abdool Karim, the director of Centre for AIDS Programme of Research in SA, will present data from the CAPRISA 004 study “to assess the safety and effectiveness of a vaginal gel containing the antiretroviral drug tenofovir” at the conference.
Tenofovir is an antiretroviral drug that is very effective in treating AIDS and it is also being tested in another big microbicide study.
“If a tenofovir gel is found to be safe and effective in preventing HIV infections in this trial, confirmatory studies involving more women will likely be required before the product could undergo an approval process by the relevant drug authorities, such as the SA Medicines Control Council,” Karim said.
The safety of over-the-counter and mail order lubricants commonly used in receptive anal sex needs to be comprehensively studied, says Jim Pickett from the organisation International Rectal Microbicides Advocates.
Findings presented at the M2010 Microbicides conference today suggested that some of the aqueous-based lubricants – with higher concentrations of dissolved sugars and salts than normally found in cells (hyperosmolar nature) – could increase the risk of getting a sexually-transmitted infection like HIV since they are associated with “cellular toxicity”.
Pickett said: “We need more data on lubricants which have not been tested for safety.”
This latest research was conducted in the laboratory and more trials are needed to get clear, validated information and to assess the clinical outcomes, said the investigator Dr Charlene Dezzutti from the University of Pittsburgh.
“One silicone (lubricant) tested seems to do much less damage than the aqueous lubricants,” she said.
She said the aqueous products damaged to the epithelial cells – the lining found in our mouth, nose, rectum and other parts of the body.
“This might lead to increased infection…these are not regulated compounds. If you are using a lubricant you might want to check the ingredient list and check it is condom friendly.”
The safest lubricants of the six tested were PRE and Wet Platinum.
Another study on lubricants in use by the participants seemed to confirm the lab findings.
Dr Pamina Gorbach from the University of California, Los Angeles, said: “Charlene showed in the lab what we found in large studies in two cities.”
The researchers were investigating the rectal health and behaviour of nearly 900 men and women in Baltimore and LA, in the US.
“More people who were using lubricants before their last receptive anal intercourse had sexually transmitted diseases. They were three times more likely to have a rectal STD.”
The participants were tested for the bacterial STDs gonorrhea and Chlamydia.
About half of them reporting using a lubricant when they last had anal sex and the majority preferred water-based lubricants.
Gorbach said: “So many types of lubricants were being used and they changed every day. Most men remembered the brand (not product) name and 20% were using more than one type.”
AN unlikely speaker took the stage this morning at the M2010 Microbicides: Building Bridges in HIV Prevention plenary, a prominent HIV vaccine researcher.
Dr Susan Buchbinder, the director of HIV research at the San Francisco Department of Public Health, presented 10 lessons from vaccine studies in which she has been involved including the STEP/Phambili Phase III efficacy trial.
Her lessons were:
# 10: Good science often yields surprising results. The findings in the RV144 Thai trial were unexpected, she said. The vaccine only provided weak cell-mediated immunity and not broadly neutralizing antibodies, yet it offered some protection against infection (an estimated 31%).
#9: Results take time to process and that analyses of the STEP/Phamibili data down the line have yielded some clues. For example, in the first three months the vaccine seemed to suppress the virus even though this effect was transient.
#8: It takes many villages for a trial: more than 16 000 volunteers were recruited for the Thai trial which was well conducted.
#7: Statistics are confusing to almost all of us. Buchbinder reported on the different analyses of the Thai trial result statistics which were released last year -and generated much controversy.
#6: Behaviour change is difficult. This is particularly relevant for microbicides, in which trials have shown that it is challenging to get volunteers to use the product appropriately.
#5: Mucosal responses are important and difficult to measure.
#4: Clinical efficacy trials are an important part of the discovery process (whether they yield the hoped for outcome or not). They provide data that cannot be gathered from non-human primates (like rhesus macaques monkeys).
#3: Transparency yields many rewards, in scientific circles and in communities. Buchbinder said the Thai researchers released their findings first to the community and subsequently opened up their data and specimens to the broader scientific community, which was a positive move.
#2 : There will be no silver bullet for HIV prevention any time soon but combined approaches can have an effect.
#1: Discovery is a multi-step process and all partners must work together. “We need multiple pieces to build combined prevention strategies,” she declared.
ANYONE who is going to take antiretroviral drugs for prevention – either orally or through a microbicide – must know his or her HIV status to avoid drug resistance developing, Dr John Mellors from the University of Pittsburgh said at the M2010 Microbicides conference today.
”If someone is infected and takes PrEP (pre-exposure prophylaxis) this would be really bad,” he said, explaining how that person would promote the spread of resistant HIV strains.
An expert on resistance, Mellors said some drug resistance among people taking antiretroviral therapy was inevitable.
About 80% of people currently on treatment have suppressed their virus. Most (4/5) of the 20% who have not, have some resistant virus.
Mellors expressed concern at the “substantial overlap in the drugs being used for treatment and those being studied for prevention”.
He said in a worst case scenario widespread resistance at a population level to these drugs could end up rendering them ineffective for both treatment and prevention.
But he added: “It is very rare to become infected with a virus we can’t treat today.”
Dr Susan Schader from McGill University said in reality resistance wasn’t an “all or nothing” problem.
Patients could increases doses, and could switch therapies if the higher levels proved toxic to them, she said.
But in South Africa and other African countries the latest, sophisticated drugs are relatively inaccessible because they cost far more than the first line treatments.
Dr Ume Abbas from the Cleveland Clinic Foundation said she had done a mathematical model on drug resistance if PrEP were to be rolled out at a population level.
“We found if an individual was already infected at baseline (in other words the person wanted PrEP not realising it was too late since they had HIV) that would be a major factor in fuelling the spread of drug resistance,” she said.
Dr Regina Osih from Wits University listed the public health concerns if PrEP were to be rolled out as adherence, resistance, the capacity of the health care system, identifying the ideal target populations and ethical choices.
Microbicide gels are acceptable to most women during sex, the results of three studies presented today at the M2010 Microbicides conference showed.
Microbicides are substances, like gels, designed to stop HIV or other sexually-transmitted infections when applied topically inside the vagina or rectum.
Significantly the one study showed that the male partner’s willingness to accept the gel was a more accurate indication of whether women would use it than whether they thought it was effective at stopping HIV.
“The gel’s acceptability was most strongly influenced by a partner’s willingness, even more than her own,” said Sharon Abbott from the Population Council in New York, whose research included information from South Africa trial sites.
“Gender and sexual norms were a better predictor of use than belief in efficacy,” said Abbott, who was assessing the acceptability of Carraguard among women.
Two gels (PRO 2000 and BUFFERGEL) evaluated in another study had about 99% acceptability.
The researcher Nicola Coumi from the Medical Research Council said that nearly half (43%) of the women expressed three or more likes, and only 3% expressed two or more dislikes of these products.
Adherence – using the gel as intended – is higher among the women who expressed positive views (several ‘likes’).
Adherence was also higher among older women, married women, those with a higher education and those who reported male condom use and douching before the start of the trial.
And roughly a fifth of the women in the MRC study found that the gels made sex more pleasurable (22% to 24%).
In another study where most participants were formal or informal sex workers, the women particularly liked the lubricant properties of the gel being tested (CONRAD’S cellulose sulfate 6%).
One woman in India even told the researchers, led by Elizabeth Green from Family Health International, that it allowed her to have more clients a day and thus earn more money.
These women suggested the gel reduced pain and reduced condom breakage.
They liked to use the product with casual partners but did not find it appropriate for their boyfriends or husbands since they thought it might ruin intimacy and trust.
“Most women liked the gel but contextual, interpersonal factors (relationships) had a stronger influence on its actual use,” Green said.
The encouraging results from Abbott’s research were that the women’s partners mostly liked it, it was easy to use during sex and when sex was routine or expected.
On the down side, it was less acceptable during a second round of sex, when partners disliked it, when sex was spontaneous or the women were away from home.
The sex acts covered ranged from 39% to 79% in this study but a biomarker (a stain on the applicator showing it was vaginally inserted) revealed that the gel was used less frequently than the women had claimed.