ANTWERP, Belgium (WOMENSENEWS)–Scientists alarmed by the limited options women have to protect themselves against AIDS are hedging their bets on a variety of vaginal gels, creams and tablets they say could one day protect women not only against HIV, but against other sexually transmitted diseases and common gynecological infections–even unwanted pregnancy.
Some 650 scientists, economists and public policy experts attended the Microbicides 2002 conference here last week to discuss their progress in developing a viable microbicide, which researchers estimate could become available as early as 2007. With an estimated 40 million people living with HIV worldwide–45 percent of them women–and microbicides endorsed last year for inclusion in the United Nations’ five-point plan to fight AIDS, their challenge is an urgent one.
In sub-Saharan Africa, which has been hardest hit by the epidemic, 55 percent of those infected with HIV are women and girls. An additional 15,000 people are infected each day around the world, say officials from UNAIDS, the United Nations agency responsible for monitoring the epidemic.
‘We Have to Create Options’
The push for microbicides reflects an expanded approach to HIV prevention, which until recently had centered largely on promotion of condoms and hope that vaccine research will bear fruit. An effective vaccine is a decade or more away, however, according to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. Even if scientists develop a vaccine that works, they say it’s unlikely to be 100 percent effective or work equally well against the various strains of HIV and the virus’ ability to mutate. The more prevention options available, the thinking now goes, the greater the chance of slowing the disease’s spread.
Mindful of these obstacles, the talk here focused on developing new methods for women to protect themselves.
"People have not given up on promoting condoms," said Sharon Hillier, a microbiologist and self-described "vaginal ecologist" who made several presentations during the conference.
"All of us recognize we have a prevention method that is very inexpensive, that is available all over, that is technically easy to use and quite effective. Given we have something that works, we are going to keep promoting it," said Hillier, director of reproductive infectious disease research at Magee-Women’s Hospital in Pittsburgh. "Having said that, we understand many people will never use condoms, so we have to create options."
Microbicides could work in several ways: They might coat virus particles or the mucosal cells of the vagina through which women are infected, preventing HIV from infiltrating those cells; they might mobilize the body’s innate immune defenses to create an unfriendly environment for the virus; they might prevent HIV from replicating; or they might prevent the virus from fusing with mucosal cells. Some microbicides could employ several of these strategies and some might be used in combination with familiar contraceptives such as condoms or diaphragms. Others may do double duty as AIDS protection and contraception.
Dr. Peter Piot, executive director of UNAIDS, cautioned the researchers here that they need to "be wary of a backlash from men" who may perceive microbicides as a reason to avoid using condoms. "It’s not an issue yet, but one could imagine that as a result of . . . microbicides that the burden will be put again on women," Piot said after opening the conference last Sunday.
Lori Heise, director of the Washington-based Global Campaign for Microbicides, agreed, noting that microbicides need to be promoted as "something that becomes part of a healthy routine rather than an emblem of distrust."
"I’m not advocating throwing away condoms," Heise said Tuesday. But "we have certain advantages with this product. It holds the potential to make sex more fun."
Lack of Funding Slows Research Efforts
At least two of the microbicides being tested are derived from naturally occurring elements in the environment. Carraguard, the only product currently in the second-to-last stage of testing required by the U.S. Food and Drug Administration before it approves a product for sale, is extracted from seaweed and is formulated as a gel that would work by preventing HIV from invading cells in the vagina. Early-stage trials found Carraguard to be safe and scientists are now testing its efficacy against HIV.
Another naturally derived microbicide, Hillier’s lactobaccillus capsule, not only appears to be safe, but seems to reduce the risk of bacterial vaginosis, a common infection among women. Hillier plans another safety trial to determine proper dosage of the capsules before testing their effectiveness against HIV, which she theorizes would work by making the vagina’s environment hostile to HIV.
Other microbicide candidates include BufferGel, which would work similarly to the lactobacillus capsules by strengthening the body’s defenses, and Pro2000, which would work similarly to Carraguard. The Invisible Condom, which is still in the early testing stages, is a "thermo-reversible" liquid that turns into an odorless, tasteless gel at body temperature and has the benefit of mimicking vaginal lubrication.
The enthusiasm of microbicide researchers for these products, however, has failed to catch on with wealthy pharmaceutical companies that typically fund drug development. Several studies, most notably a February report commissioned by the Rockefeller Foundation, found that microbicides would eventually tap a projected $1.8 billion annual market worldwide and avert 2.5 million infections over three years. But the report also found that sales of the first generation of microbicides wouldn’t cover companies’ cost of investing in their development. The task has consequently fallen to foundations and governments, but funds available for clinical trials fall far short of the amount needed, says Arnon Mishkin of the Boston Consulting Group, who studied the problem.
This year’s estimated microbicides budget for the U.S. National Institutes of Health, for example, is $55.7 million and is expected to grow to $68.2 million next year.
New Jersey Democratic Sen. Jon Corzine, noting that the funds represent less than 2 percent of the institutes’ total AIDS research budget, says the government isn’t spending enough on the research. He has proposed a bill that would increase the institutes’ research dollars with the goal of getting a product to market in five years.
The federally funded health research center invests heavily in developing an AIDS vaccine that is more than 10 years away from productive use, Corzine said, but "it has no program dedicated to researching microbicides that could be developed much sooner."
Corzine, who took an interest in microbicides after learning that his state had the highest prevalence of female HIV infections in the country, said that "developing a vaccine is an important long-term project, but in the short term, we need new methods to prevent the spread of AIDS."
Fulvia Veronese, who oversees the institutes’ microbicide work, said that the agency doesn’t place a higher priority on vaccines than on microbicides, even though it officially formalized programs on microbicides and on preventing HIV in women and girls only last year.
"We think that both are high priorities," Veronese said, adding that the agency was actively trying to recruit investigators to work on microbicides. Vaccine research gets "a larger budget because it started as a larger budget. There was a period when they also had to struggle. Microbicides are following the same type of process."
Veronese was asked whether the Bush administration’s stance on reproductive health–including a nine-month freeze of funds that would aid international reproductive health efforts and advocacy of abstinence-only sex education–might threaten the proposed expansion of investigators’ work.
"I can’t comment on that," she said.
Jordan Lite is assistant managing editor of Women’s Enews.
For more information:
Microbicides 2002 conference:
National Institutes of Health
Microbicides HIV/AIDS-Related Research:
Global Campaign for Microbicides: