printable versionMicrobicides and circumcision: Conference highlights new preventive tools
BY RUTHANN RICHTER
“Granny” AIDS activists from Africa and Canada joined a parade in downtown Toronto organized by UN Special Envoy for AIDS Stephen Lewis.
For every person receiving antiretroviral drugs for AIDS, there are as many as 10 others who are newly infected with the virus. At that rate, the cost of achieving the goal of universal access to AIDS treatment would be a staggering $13 billion a year, Bill Gates said in opening the 16th International AIDS Conference in Toronto.
"You quickly see that there's no feasible way to do what morality requires—treat everyone with HIV—unless we dramatically reduce the number of new infections," he said to thunderous applause.
Prevention proved to be the mantra of the six-day conference, which ended Aug. 18. The colossal event had the feel of a pep rally, with speakers exhorting attendees—a record 26,000 from 170 nations—to redouble their efforts to stop the spread of AIDS. Global leaders, such as Gates and former President Bill Clinton, called it an urgent priority to develop and put in place new prevention tools, such as microbicide gels for women and circumcision for men.
"We all know the harsh reality that we're quickly falling behind," said Helene Gayle, MD, the conference co-chair and president of the International AIDS Society. Without new, broad-scale prevention programs, "there is no hope of bringing this epidemic under control," she said.
The conference, with its inch-thick program and 2,400 scientific abstracts, offered delegates a dizzying menu of information and events. It also had its usual share of color, with a parade of African grannies in downtown Toronto, a march for women's rights and demonstrators in white coats who interrupted sessions to call attention to the shortage of nurses in the developing world.
On the scientific side, the conference featured frustrated hopes for an AIDS vaccine, with one top researcher, Francoise Barrè-Sinoussi of the Institut Pasteur in Paris, questioning whether it's even feasible. Gayle quickly disagreed, saying she believes the scientific obstacles can be overcome, but she was unwilling to predict how long it will take.
With a vaccine still far away, world leaders turned their attention to other prevention options that could be implemented sooner.
Bill and Melinda Gates, whose foundation recently poured another $500 million into the AIDS fight, said they plan to invest additional resources into the development of a microbicide, a clear, odorless gel that women can apply to kill the virus during sexual contact. Peter Piot, MD, director of UNAIDS, also called for a doubling of public funding for research on microbicide development. The value of microbicides is that they would give women the power to protect themselves against infection during sex—something many women now lack, speakers said.
Women are disproportionately affected by AIDS, accounting for 57 percent of infected people in sub-Saharan Africa. Worldwide, more than half of the estimated 38.6 million people living with HIV are women. With the number of infected women on the rise, empowering women became a key theme of the conference.
Currently, there are five candidate microbicides in clinical trials, with early results expected in 2007 or 2008. If these prove viable, they could reach the market by 2010, experts said.
Clinton touted the potential value of circumcision, which he said could have a "staggering impact" in reducing infection rates. Circumcision is believed to reduce HIV risk by eliminating the Langerhans cells on the foreskin of the penis, which are highly susceptible to HIV. Last year, a study of 3,274 South African men showed that those who had the procedure had a 60 percent lower risk of becoming infected with HIV from a female partners.
Still, the World Health Organization and UNAIDS have been loath to recommend widespread use of circumcision until larger studies confirm its efficacy. Trials are under way among 8,000 men in Kenya and Uganda; preliminary results from the Kenyan trial, presented at the meeting, showed that as many as two-thirds of the men were protected against infection. Full results are expected in 2007. In a trial in Uganda, researchers are following 7,000 women to see if circumcising their partners may stop the women from contracting HIV.
Even if circumcision is found to be effective, it faces obstacles of cultural acceptability and a shortage of sterile facilities in developing countries for the procedure. "We will have a big job of selling it and providing safe, effective and rapid ways of doing it," Clinton said.
While acknowledging the need for scaled-up prevention programs, Christina Pimenta, PhD, executive director of the Brazilian Interdisciplinary AIDS Association, cautioned against an over-reliance on biomedical approaches, which she said are not "magical solutions." Brazil has effectively marshaled community-based organizations to deliver prevention messages and thereby reduce infection rates.
"We have to be careful not to go for medicalization of prevention," Pimenta said at a plenary session. "Because even with these technologies, we're talking about people, and we're talking about behavior and attitudes."
Ruthann Richter, the School of Medicine's media relations director, attended the world AIDS conference in Toronto.
