Mapping Pathways is a multi-national project to develop and nurture a research-driven, community-led global understanding of the emerging evidence base around the adoption of antiretroviral-based prevention strategies to end the HIV/AIDS epidemic. The evidence base is more than results from clinical trials - it must include stakeholder and community perspectives as well.

21 April 2011

The Big Picture: Pay off the Mortgage Early for Big Savings Later on

The hottest topic in HIV prevention these days is the use of antiretroviral (ARV) therapies to prevent transmission of the disease. These drugs are typically used to treat people living with HIV, but are being studied for ways in which they can actually prevent HIV as well.

There are several ways in which ARVs can be harnessed to prevent onward transmission. The first is getting more people living with HIV tested and into treatment. This approach, known as Test and Treat, Treatment as Prevention, and TLC+ (test, linkage to care, plus treatment) has been gaining currency in the last several years. Since people on treatment with undetectable viral loads are less likely to transmit HIV, it stands to reason that testing and linkage to care and treatment can reduce new infections in a community. The lower the “community viral load”, the much less likely an individual will come into contact with someone who could pass on HIV infection.

At the recent American Conference on Treatment for HIV, Julio Montaner, MD, of the University of British Columbia in Vancouver, likened putting people living with HIV on treatment as a mortgage – the more you pay now, the less you pay later. And researchers in San Francisco, where an aggressive new “Test and Treat” policy has been underway, have predicted they could reduce the infection rate among gay men and other men who have sex with men (MSM) by more than 60% over the next eight years if everyone diagnosed with an HIV infection began taking ARV drugs right away.

The other two methods utilizing ARVs as prevention involve providing the drugs to HIV-negative people, either orally, or through topical application in the vagina or the rectum. Oral prevention is known as PrEP (pre-exposure prophylaxis) and the topical application is known as a microbicide.

Two clinical trials testing these strategies – one in which women tested an ARV-gel vaginally and the other where gay men and other MSM took an ARV tablet by mouth – showed significant efficacy and reported their findings in the second half of 2010.

In July 2010 at the International AIDS Conference in Vienna, the Centre for AIDS Programme of Research in South Africa (CAPRISA) announced ground-breaking results from the first clinical trial to show that a microbicide could prevent HIV infection. The findings demonstrated that women who used a vaginal gel containing an ARV called tenofovir were 39% less likely to be infected with HIV compared to those using a placebo gel. Among women who were most adherent, the tenofovir gel decreased the chances of HIV infection by more than 50%. Interestingly, tenofovir gel also reduced a woman’s risk of contracting herpes simplex virus type 2 (a permanent and incurable infection that can increase the risk of HIV infection) by more than half. The trial’s findings need to be confirmed. A large multinational trial among 5,000 African women in Zimbabwe, Uganda, and South Africa called VOICE is currently comparing ARV oral tablets (Truvada and tenofovir) to ARV vaginal gel (tenofovir) formulations and could report results in 2012.

The second trial, a large multinational trial known as iPrEx, was “aimed at determining whether two ARV medications used to treat HIV/AIDS help prevent HIV acquisition in HIV-uninfected people at high risk of infection” ( In results published in the New England Medical Journal in November 2010, the iPrEx trial reported a 43.8% reduction in HIV acquisition by gay men and other MSM who took a Truvada tablet daily, compared to a placebo. Truvada is a combination product comprised of two different ARVs. Other PrEP trials among women, sero-discordant heterosexual couples, and injection drug users will report their data in the next couple of years.

So what exactly do these studies mean, and why are their findings significant? It is nothing short of a prevention revolution. The field has discovered two new strategies for preventing sexual transmission of HIV, and a future where individuals have more options to protect themselves beyond condoms is no longer just a theory, or a dream. ARVs, whether in the form of microbicides or pills, can be used as a strategy for prevention as well as treatment. Equally promising, treating people right after diagnosis (as opposed to waiting) will have a clear impact – it is unclear how big that will be – on the future of the epidemic.

While these findings are hopeful, they are still very preliminary and further testing is needed to confirm the results. Therefore, communities and policymakers are grappling with how they will incorporate this new information into their existing HIV/AIDS programs, systems, and structures. Complex questions around cost, accessibility, acceptability, resistance, long-term side-effects, infrastructure, and implementation remain to be answered.

This is where the Mapping Pathways initiative enters the picture. We feel that there is a clear and pressing need to provide these key stakeholders with the analysis and research that they need to form a well-rounded response to the rapidly changing scientific, socio-economic, and socio- political contexts in which intervention initiatives occur. In this way, we hope to map pathways to good decision-making for HIV prevention, intervention, and treatment options.

This blog is a space to record our journey as we gather information and, more importantly, to capture and encourage conversations about the challenges, successes, and debates that are shaping this pivotal crossroads in HIV/AIDs prevention and eradication history.

[Content that is linked from other sources is for informational purposes and should not construe a Mapping Pathways position.]

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