AIDS 2012: Combination Prevention
By Regina McEnery
The last time the International AIDS Conference was held in Washington, D.C, the number of antiviral drugs licensed to treat AIDS was zero. That was in 1987, and US regulatory approval for zidovudine (AZT) was still a year away. But it was already clear that the pandemic was escalating at a frightening pace, and the US Public Health Service placed national travel and immigration restrictions on people with HIV. Activists in the country, meanwhile, mobilized to form the AIDS Coalition to Unleash Power—or ACT UP—to push researchers to find effective treatments for their dying loved ones. Half a world away, Ugandans established the first AIDS clinic in Africa and, in 1987, The AIDS Support Organization (TASO) began providing quality care for HIV-infected people.
A quarter century later, with the biannual conference once again at the doorstep of the US Capitol, the landscape and mood of the 19th International AIDS Conference—AIDS 2012 for short—will look and feel profoundly different, even if the ultimate message of both meetings remains the same. For one, the 25,000 attendees expected to attend the event, which will take place July 22-27, and will include keynote talks from Elton John, Bill Clinton, and Bill Gates—is a much larger group than the 6,000 who attended the 1987 meeting, though it could be argued the 1987 conference was more newsworthy. An astounding 900 journalists covered those proceedings.
The AIDS Memorial Quilt, a powerful and poignant reminder of how many lives have been impacted by AIDS, will be on full display this month in Washington, D.C. Due to its sheer size, the 48,000 hand-sewn panels that now make up the quilt can’t be viewed at once. Instead, portions will be spread out at 60 different distinct exhibits in the US capitol, primarily the National Mall, which will display 8,800 different panels a day from July 21-25. A gay activist is credited with sewing the first 3 x 6 foot panel in 1987. The quilt now contains panels from every US state and from many parts of the globe. According to the NAMES Project Foundation, caretaker of the quilt, Barbie dolls, stuffed animals, car keys, bubble wrap, Legos, tennis shoes, credit cards and a Sony Walkman have all been used to assemble quilt panels. The foundation said it took more than nine months for all the quilt panels on loan to community groups for education purposes to be returned to the foundation to be prepared and packed for the journey to Washington. The last time the AIDS quilt was on full display was in October 1996, when it covered the entire National Mall.
The location of the conference is also seen as symbolic, and not because a US presidency hangs in the balance. The last time the conference was held in the US was in 1990. The International AIDS Society—which sponsors the meeting—decided to host the conference in Washington, D.C., after the Obama administration announced, in December 2009, that it was lifting the controversial travel ban on HIV-infected people. Former International AIDS Society (IAS) president Julio Montaner had previously noted that the ban had no scientific or public health merit (seeVAX Dec. 2009 Spotlight article, A Year of Progress).
IAS president Elly Katabira, who helped start TASO, is presiding over AIDS 2012. It is billed as the largest conference dedicated to a single issue and its theme this year is “Turning the Tide Together.”
There has been much progress in HIV treatment since the conference was last held here. Today, an arsenal of some 30 antiretroviral drugs are available for the treatment of the HIV infected. The drugs have been highly effective in suppressing HIV in those fortunate enough to have access to them. Some have even been found to be effective, in some instances highly effective, in reducing HIV transmission. The US Food and Drug Administration is expected to rule in September on whether the ARV known as Truvada—a combination of the drugs tenofovir and emtricitabine—may be used for HIV prevention in certain high-risk populations (see Primer, this issue). Further, a recent international trial found earlier ARV treatment of HIV-infected individuals reduced HIV transmission to their HIV-uninfected partners by 96%.
ARVs are not the only bright spot. Adult male circumcision, another effective strategy for curtailing HIV transmission, is expanding in sub-Saharan Africa. The arduous hunt for an effective vaccine has been buoyed in recent years by a series of clinical and preclinical breakthroughs. And scientists are even launching research programs to accomplish what was until relatively recently considered pretty much impossible—curing HIV infection.
Dr. Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases (NIAID) and a speaker at the 1987 meeting, recalled how bleak the atmosphere was back then. “AZT wasn’t widely used and it was only a single drug. Its effect was short-lived,” he says. “We had a raging epidemic with an infection rate exploding in front of our eyes. And we didn’t even fully realize what it was like in the developing world.”
Fauci will be giving the opening plenary talk at AIDS 2012 on July 23, and he’ll have far more scientific tools to highlight this time around, though the global economic slump threatens funding for their development. “Our challenge is to work collectively to implement these proven interventions in order to make an AIDS-free generation truly possible,” wrote Fauci and his chief of staff, Gregory Folkers, in a recent blog post in advance of the conference. “This will require increased financial resources, innovation, political will, an overall strengthening of health systems, fighting stigma, and greater ownership by all countries of HIV/AIDS efforts within their borders.”
A July 25 plenary address will focus exclusively on AIDS vaccines (see Q&A with Barton Haynes, this issue), and about two dozen talks will focus on vaccine science. But vaccines will not be a major presence at this meeting of 3,500 oral abstracts and dozens of satellite and special sessions.
Bill Snow, the Global HIV Vaccine Enterprise’s new director, says the limited number of vaccine talks isn’t surprising. “I think that it has always been the case that vaccines have been underplayed, largely because of IAS and because of who comes to these meetings,” says Snow. “There is always an immediacy to these conferences, always something people need to change right away. The social and political agenda has driven everything, which I do think is fabulous and really important.”
Snow says resources for AIDS research are clearly flat, which is overshadowing the scientific discussions, provoking calls for greater collaboration between researchers and funders, and forcing funders to make tough choices on which projects to keep funding and which ones to sideline. At the same time, he says, the field is increasingly focused on studying different prevention strategies together—such as pre-exposure prophylaxis (PrEP) with a vaccine candidate—because such approaches might dramatically lower HIV incidence in some high-risk populations.
“There is really a lot of work and thought going on into how trials will fit together, what the prevention package will be relative to the intervention tested, and how that is played out,” he says. “The funding crisis is really causing people to focus and prioritize, which is not a bad thing.”
Some advocates and researchers are now pushing for universal access to testing and treatment as a way to end the pandemic. But Mark Dybul, co-director of the global health law program at Georgetown University’s O’Neill Institute, who led the implementation of the President’s Emergency Program for AIDS Relief (PEPFAR) under US President George W. Bush, says there is no silver bullet that can eradicate HIV. “What a lot of us are talking about is combination prevention and really focusing on high transmission geographies and populations, because in different countries and in different parts of different countries, there are different drivers of the epidemic,” he says.
“There has already been a greater than 25% reduction in HIV incidence in 33 countries, 22 of them in sub-Saharan Africa,” says Dybul. “In some countries, the declines are as high as 40% to 60%.” He says countries need to be smart and focused on where the epidemics are occurring because there aren’t going to be resources to cover every country with every intervention.
Mitchell Warren, executive director of AVAC, based in New York, says the AIDS 2012 conference will predominantly be about making the right decisions about allocating resources for the future. “For instance, how do we optimize ARVs for treatment and prevention? How can we scale up adult male circumcision now? How can we bend the curve of the epidemic today?”
Warren says the global momentum to address the AIDS epidemic using scientifically proven methods, such as oral and topical ARV-based prevention and adult male circumcision, would undoubtedly save lives, prevent new infections, and lower the price tag for the global AIDS response over time. But he says a vaccine is still needed if the world wants to end the epidemic once and for all. “There will be people [at AIDS 2012] in D.C. who say that if we test and treat everyone who is HIV infected that will be enough to end the epidemic. Others will say that is not enough, that PrEP has a role. And male circumcision is important. The bottom line is they are all right, but how do we move beyond the technology that is specifically being championed and into a decision-making mode that pulls the pieces together?” wonders Warren.
At the same time, he says, sustained funding is needed for AIDS vaccine scientists to continue producing breakthroughs, such as the discovery of new and more potent broadly neutralizing antibodies that has helped breathe new life into antibody-based research. He also says the AIDS vaccine field needs to set and communicate milestones for measuring progress in order to keep the pipeline of vaccine candidates robust and flexible.
Warren says that, ideally, a vaccine would be cheap, easy to administer, and offer lifelong protection after a single immunization, unlike the more complex six-shot regimen that was tested in the RV144 trial that in 2009 demonstrated the first evidence of vaccine-induced efficacy (see VAX Sep. 2009 Spotlight article, First Evidence of Efficacy from Large-Scale HIV Vaccine Trial). “Someday, an AIDS vaccine might fit that description,” he says.