"As soon as it was suggested that nonoxynol-9 was effective against HIV during vaginal intercourse, word quickly spread among gay men who started using lubricants with nonoxynol-9 for anal sex," said Alex Carballo-Diéguez, researcher in New York City. Research has documented that a substantial percentage of gay men seek out and preferentially buy lubricants containing N-9 (41 percent according to one study).

Even condoms lubricated with N-9 may be slightly riskier to use than plain lubricated condoms, according to the CDC.

Unfortunately, recent data also show that N-9 can also irritate both rectal and vaginal tissues -- thus potentially making it easier for HIV to get into the blood stream of the receptive sex partner. A recent study of gay men using N-9 lubricants showed that it caused the surface of the rectal lining to slough off "in great sheets of cells". Although the cells grow back after a few hours, the sloughing temporarily strips off the rectum's first line of defense and increases vulnerability to infection. The CDC is now recommending against the use of N-9 products for disease prevention. Even condoms lubricated with N-9 may be slightly riskier to use than plain lubricated condoms, according to the CDC.

So what will microbicides look like?
The new rectal microbicides, when available, are likely to be packaged as lubes, gels and perhaps suppositories. Some will be designed for insertion several hours in advance while others, like lubes, will be products used right before sex. Several of the new microbicides are likely to help protect against a range of other STDs, as well as HIV.

The end goal is to make microbicides that enhance pleasure, as well as safety, so that people have an extra incentive to protect themselves.

 
 
In June, the NIH funded a pivotal meeting of the leading scientists engaged in rectal microbicide research who identified key questions that must be answered: how much product is needed to get a protective effect; what will the applicators look like; what effect will these products have on the rectal lining? Above all, how do we make sure the microbicides are acceptable in terms of feel, smell and taste? The end goal is to make microbicides that enhance pleasure, as well as safety, so that people have an extra incentive to protect themselves.

How will they work?
How a product works, or its "mechanism of action", is different for different candidates. Some reduce transmission risk by killing or inactivating the pathogens present in seminal or vaginal secretions. Others focus instead on reducing acquisition risk, or the odds of HIV or other STDs to enter the blood stream of the receptive sex partner.

Here's an example of a "mechanism of action" being explored in the first category. It is possible that antiretroviral drugs, originally designed to keep HIV from reproducing in people living with the virus, could be reformulated as topical microbicides and used to inactivate any HIV that enters the rectum or vagina during sex. At least two such drugs have now been reformulated as vaginal gels and are expected to enter vaginal safety trials, with penile and rectal irritation trials to follow.

Examples of "mechanisms of action" in the second category include PRO 2000™, a gel that keeps HIV, HSV (herpes virus) and the bacteria that cause gonorrhea and chlamydia from attaching to cell walls. Women enrolled in small-scale trials have used it without vaginal irritation. A larger vaginal-use study is now slated, as are penile and rectal irritation studies among men.

Another leading candidate in the second category, Carraguard, also blocks attachment. Made from carrageenan, a seaweed-derived emulsifier commonly used as a food and cosmetics additive, Carraguard appears to be safe for vaginal use and capable of reducing risk of HIV, HSV, gonorrhea and HPV (human papalloma virus) infection. Large-scale effectiveness trials measuring its effectiveness among women in "real world" conditions will start next year, as will rectal safety and acceptability studies among gay men.

How effective will microbicides be compared to condoms?
Researchers and advocates agree that it is highly unlikely that a microbicide alone will ever be as effective as a condom. Obviously, it's safer to keep viruses and other germs out of the body altogether than it is to try to neutralize them once they're there. Even when microbicides reach the market, using condoms every time will still be the best option for disease prevention.

Researchers and advocates agree that it is highly unlikely that a microbicide alone will ever be as effective as a condom.

It's equally obvious, however, that even a moderately effective microbicide will work far better than a condom left in the drawer. Microbicides will provide a valuable back-up for people who want additional protection in case the condom breaks or leaks. Just as importantly, they will provide another prevention option for people who can't or don't use condoms every time.

A lot of people don't use condoms regularly. The vast majority of gay men, however, do use lubes regularly for anal sex whether or not they are using condoms. A microbicidal lube, therefore -- even one that is only 50 percent to 70 percent effective in preventing infection -- could dramatically reduce the number of new STD and HIV infections among men who aren't using condoms.

Public debate over "barebacking" highlights the fact that one tool for disease prevention just isn't enough. People protect themselves most effectively when they have a range of options from which to choose. Microbicides could offer an alternative to the current "condom versus no condom" decision. Microbicides are harm-reduction. When used in place of no protection at all, they will prevent at least some infections and will save some lives.

So when do we get them?
That depends on all of us. Right now, microbicide research is woefully underfunded. Large pharmaceutical companies -- the normal engines of product development -- aren't investing in developing them because doubt that such over-the-counter prevention products will be profitable enough to recoup the cost of developing them.

Microbicide research and development (R&D), therefore, is being done almost exclusively by non-profit entities, academic researchers, and small bio-pharmaceutical companies, all dependent on government and foundation grants to pursue their research. At present, the NIH invests about one percent of its AIDS-related research budget ($34 million annually) in microbicide R&D.

If we expand the amount of money invested in microbicide R&D, we are likely to see new products on the shelves in five to seven years. If we don't, it will take significantly longer.

In June, Congresswoman Connie Morella (R-MD) introduced the Microbicides Development Act of 2001 (HR 2405), legislation that would boost the federal budget for microbicide R & D enough to assure that testing moves forward efficiently.

Researchers report that it's perfectly possible to develop effective microbicides. Gay men report that they want lubes that prevent infection and will use them if given the chance. And the numbers -- not only of new HIV cases but also of gonorrhea and syphilis infections among gay men -- testify loudly to the fact that condoms just aren't enough.

So isn't it time to demand new prevention tools; ones that can be used with, or instead of, condoms? Twenty years into the HIV pandemic, isn't it time to demand microbicides?

For more information on gay men and microbicides, please go to www.lifelube.org.

For more information on supporting the Microbicides Development Act of 2001 and/or educating others about microbicides, please contact the Global Campaign for Microbicides by phone: 202-454-5048, or on the Web at www.global-campaign.org.

Updated: Thursday, February 21st 2002