The 19th International AIDS Conference ended July 27 on an optimistic note, with speakers presenting a vision of an "AIDS-free generation," despite the myriad economic, social and scientific barriers that remain. And for the first time, scientists dared to talk seriously about an AIDS "cure," an admittedly daunting technical challenge.

Eran Bendavid

"We are at a defining moment," said Diane Havlir, MD, conference co-chair and professor of medicine at UC-San Francisco. "It would be an extraordinary failure of global will and conscience if financial constraints truncated our ability to end AIDS just when the science is showing us this goal is achievable."

Some 24,000 people from 183 countries attended the biannual gathering, held this year in Washington, D.C. Always a colorful, cacophonous event, this year's conference featured more than its share of public policy discussion, with presentations by Secretary of State Hillary Clinton, Sens. John Kerry, D-Mass., and Lindsey Graham, R-S.C., and Rep. Barbara Lee, D-Oakland.

The world is gaining ground against AIDS, with more people now on treatment (8 million) than those who need it (7 million), said Michel Sidibe, executive director of the Joint United Nations Program on HIV/AIDS, also known as UNAIDS. Worldwide infections have declined 20 percent since 2011, and in hard-hit Africa, AIDS-related deaths have fallen from 1.8 million in 2005 to 1.2 million today, he said.

Still, there are 34 million people living today with HIV, and for every person on treatment, two more become infected, highlighting the need for stepped-up prevention efforts, speakers said. And though 100,000 fewer babies were born HIV-positive in 2010, there were still some 330,000 infants who became infected at birth or through breastfeeding in 2011. Clinton, who announced an $80 million initiative to prevent mother-to-child transmission, said the goal is to reduce this number to zero by 2015.

The advancing science of AIDS, meanwhile, has produced a plethora of new treatments and prevention strategies that could help drive down AIDS prevalence. These include voluntary male circumcision, use of anti-AIDS drugs in infected individuals to reduce their chance of passing on the virus to others, as well as use of these drugs as preventives in uninfected people.

Yet it is unclear how all of these strategies will be implemented and whether funds will become available to put them into action.

"There is the thinking that we can bend the curve downward in a substantive way, but money is flat, which creates some very obvious tension," Eran Bendavid, MD, assistant professor of medicine at Stanford, said in an interview at the conference.

AIDS funding has remained constant since 2008 and, with the decline in contributions from some of the wealthier nations, there remains at least a $7 billion gap in funding to achieve universal access to HIV prevention, treatment, care and support by 2015 - a major UNAIDS goal, Sidibe said. The perennial issue of funding shortages sparked a number of demonstrations during the conference, including a march on the White House by protesters calling for lower-cost AIDS drugs and more resources.

Mark Holodniy

This is the first time in 22 years that the conference has been held in the United States, putting the spotlight on the domestic epidemic, which continues out of control. An estimated 1.2 million Americans are believed to be infected with the virus, and 20 percent don't even know it, said Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases. Each year, 50,000 more are added to the ranks of infected people. Moreover, only 28 percent of those infected are linked to care and stick with it long enough to bring the disease under control, he said.

"In the richest nation on the planet, barely a quarter (of those infected) are on effective treatment," said Phil Wilson, president and CEO of the Black AIDS Institute. "That is bad for them and bad for the rest of us. Because if they are not on treatment, they are much more likely to spread the virus."

Mark Holodniy, MD, professor of medicine at Stanford, said he sees this problem among the 200 HIV patients at the Palo Alto Veterans Affairs Health Care System. Many don't take their medications for a variety of reasons - mental health problems, substance abuse, incarceration, multiple medical issues or simply because they can't get to a clinic, he said. The VA is one of the largest HIV providers in the United States, with 25,000 patients at 152 sites.

"HIV in the veteran population is a big problem, and we're constantly trying to improve access and services. We have a ways to go," Holodniy said. "If we can figure it out here, we can export it to Africa" and other areas of high prevalence.

Holodniy said it's unclear how some of the new AIDS-fighting technologies will be implemented locally. For instance, the U.S. Food and Drug Administration recently approved the antiretroviral drug Truvada as a form of prevention in uninfected people, as studies have shown it can reduce risk of infection by as much as 72 percent when taken conscientiously by the uninfected person.

"The studies are compelling that it has significant impact on reducing infection," he said. "But there are costs, and there are toxicities."

Because the drug is expensive - almost $10,000 a year - it would only be cost-effective to use it in select, high-risk groups, according to a study published in April by Bendavid. So issues remain about who will pay, as well as how to target appropriate groups and ensure that those taking the drug continue to follow safe sex practices and be monitored for side effects. "There are a lot of questions about how it will work in the real world," Bendavid said.

In other scientific developments, researchers unveiled a new effort, involving a team of scientists from around the world, to find an AIDS cure. What makes HIV eradication so challenging is the fact that the virus integrates itself into the DNA of specialized immune system cells and can persist there indefinitely without detection. Scientists are just starting to develop tests to measure these latent cells not only in the blood, but in other body tissues, such as the lymph nodes or genital tract, where they may be hiding, said Javier Martinez-Picado, PhD, a senior investigator at IrsiCaixa AIDS Research Institute in Barcelona.

David Margolis MD, of the University of North Carolina-Chapel Hill, reported some success in the use of the cancer drug Vorinostat to lure the cells out of hiding. In theory, antiretrovirals then could be used to mop them up.

"Certainly, this is promising," Martinez-Picado said.

Still, scientists cautioned that the technical obstacles to a cure could be insurmountable.

"Getting something into the lymph nodes, liver and brain, homing in on those cells and destroying those cells is a bit of a tall order," Holodniy said.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital.

For more information, please visit the Office of Communication & Public Affairs site at http://mednews.stanford.edu/.

Source: Health Canal