AIDS prevention for women.

AIDS prevention for women.

AIDS prevention for women.

Health and medicine explained.
March 8 2005 12:15 PM

Good Goop

A new method of AIDS prevention for women.

Bravely, it must be said, the Senate will celebrate International Women's Day today by talking about microbicides—vaginal gels, creams, and other products that women could use topically before sex to protect themselves from HIV. Sens. Jon Corzine, Barack Obama, and Olympia Snowe are introducing a bill that would increase funding for microbicide research and coordinate the efforts of the government agencies that do it.

Microbicides have long been high on the wish list of grass-roots activists, who see them as the most promising way to prevent AIDS for heterosexual women at high risk of infection from unfaithful husbands or partners, especially in Asia and Africa. Many of these women can't easily insist that their men use condoms. Microbicides, on the other hand, are a form of prevention that they can control themselves. Yet to date, research related to their development represents only 2 percent of all AIDS spending by the National Institutes of Health. Legislators have been reluctant to champion a cause that, well, smacks of sex, and the scientific establishment hasn't been particularly responsive either. But now, with today's bill and five candidate products entering or about to enter large-scale effectiveness trials around the world, it may be that microbicides' time has come—as long as conservative leaders and top brass at the NIH stay tuned to their potential.

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The case for microbicides is backed by persuasive numbers. Heterosexual women increasingly bear the brunt of the AIDS epidemic to the tune of roughly 7,000 women and girls newly infected each day. Microbicides aren't a cure-all, but they could do a lot of good in high-risk areas, even if just some of the people there were to use a somewhat effective microbicide some of the time. One mathematical model, which focused on Johannesburg, South Africa, predicted that if 75 percent of area residents were to use a 40-percent-effective microbicide in half of the sexual encounters in which they didn't use condoms, the local incidence of HIV infection would drop by 9 percent. That may not sound like much, but across countries and continents, similar percentages could translate into millions of saved lives.

Microbicides could be a particular boon to married women. While condoms have been successful in slowing the spread of AIDS among commercial sex workers and others, their association with illicit sex makes many long-term couples reluctant to use them. A woman who asks her husband to wear one may seem confrontational. The nice thing about microbicides, by contrast, is that they need not be discussed in the heat of the moment. According to Dr. Lori Heise, director of the Global Campaign for Microbicides, "Women say, 'I can tell him once, in the kitchen, then never talk about it again'." Another appeal is that some microbicides are not contraceptives, which means that women who want to get pregnant won't have to choose between exposing themselves to infection and having kids.

Despite strong community interest, however, microbicides have had a hard time winning friends in high places in the United States. Over the years, advocates have repeatedly been turned away when they begged to meet with congressional staffers. The problem isn't vociferous opposition. It's that few legislators are willing to put themselves on the line for a product that makes them blush. We are talking, after all, about goop for the vagina (as opposed to, say, a vaccine that can be injected neatly into the arm). Which means that we're talking about sex. In the current climate, abstinence-only prevention programs are the preferred conservative response to AIDS, and some potential supporters may have a hard time fitting microbicides into that no-sex message (never mind that even a hard-liner wouldn't argue that married women shouldn't have sex with their husbands).

With a little finesse, conservatives as well as liberals should be able to embrace a method of AIDS prevention geared toward faithful married women. Yet with the exception of Republicans like Olympia Snowe and Connie Morella, a moderate who lost her House seat three years ago, the party leadership has pushed microbicides to the margins. The bipartisan AIDS bill introduced in May 2002 included increased support for microbicides, but the provision was quietly dropped when the Republicans recast the legislation after regaining control of the Senate later that year.

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If Congress' hesitancy to date is predictable (if silly), what's the scientific establishment's hangup? NIH could have allocated more of its total AIDS budget for microbicides if it wanted to, even without congressional prodding.

In the past, it's been tough for hard-core basic scientists to get excited about microbicide research. The products now undergoing effectiveness trials are large, sticky molecules that act in different ways to thwart HIV: They may increase the vagina's acidity and make it inhospitable to the virus; they may act like detergents and disrupt the viral membrane; or they may block or interrupt attachment of the virus to vaginal cells. These are techniques with great appeal to public health researchers. But they're not the sort of thing for which anyone wins a Nobel Prize. Nor are they likely to yield cash-cow products. Two companies, GlaxoSmithKline and Tibotec, a Belgian subsidiary of Johnson & Johnson, have agreed to let researchers test proprietary anti-HIV compounds to see if they might work as microbicides. But the drug industry has put up virtually no money, and all told its involvement has been miniscule.

NIH traditionally favors vaccine research, which involves some very complex, highbrow science. Microbicide advocates would welcome an AIDS vaccine, of course, as they say often and loudly. But they argue that with research proceeding much more slowly than expected—and no viable vaccine candidate on the horizon—it's time to pay attention to goop. There are signs that the scientific elite is beginning to come around. Federal funding for microbicides rose from $34.6 million in 2000 to an estimated $88.8 million in 2004; if passed, the bill introduced in the Senate today would establish a dedicated microbicides team within the NIH and likely result in further spending hikes. And on World AIDS day in December, Dr. Anthony Fauci, head of the NIH institute that oversees the bulk of AIDS research, included microbicides in his widely cited statement on women and AIDS. It may help that the next generation of microbicides, which will succeed the products currently in effectiveness trials, includes scientifically jazzier formulations based on newer and more detailed knowledge of HIV's life cycle and means of transmission. Combination formulations that deploy several active ingredients, each with the potential to thwart HIV in a different way, are also in the works, and they tend to excite the basic-science crowd.

All this comes as welcome news, since microbicides have the potential to do enormous good. Goop for the vagina may not get senators re-elected; it may not turn scientists into rock stars. But as an AIDS-prevention method, current microbicides are both promising and relatively simple, which means theycould be cheaply made and copied. And that makes speeding along their development especially important.