Condoms are good, but a lot of folks don’t use them; mutual monogamy doesn’t always work out; and, abstinence is practically a joke. So, how else can people protect themselves from HIV infection? Microbicides might be just the thing. Similar in concept to spermicides, microbicides are solutions that, when applied to the vagina or rectum, kill viruses before they can infect a person. Since the early 90s, researchers have been trying to develop microbicides to prevent HIV transmission. Along with adding another weapon to the war against HIV/AIDS, microbicides will be the first form of protection for women that does not require a male partner’s cooperation.

What Are Microbicides?

A topical microbicide is any cream, gel, suppository, film, sponge or foam that, when applied or inserted into the vagina or rectum prior to sexual intercourse, prevents HIV or other sexually transmitted infections. Microbicides may even prevent pregnancy. There are no microbicides available yet but several are being tested on humans.

Under Investigation

Among the vaginal microbicides currently being tested on humans are:

• PRO 2000, developed by Indevus Pharmaceuticals, is being tested in large numbers of women to see if it can prevent HIV and other disease-causing organisms—such as herpes, chlamydia and gonorrhea—from entering healthy cells.

• Carraguard®, one of Population Council’s microbicides, is a gel made from carrageenan. A seaweed extract, carrageenan is used in lotions and creams, as well as in some foods. It is hoped that Carraguard® will be able to prevent infection from HIV, herpes, HPV, chlamydia and gonorrhea.

• BufferGel®, developed by ReProtect, has been designed to maintain the naturally mild, protective acidity of the vagina. This should allow it to prevent pregnancy by killing sperm (normally, the fluids that make up a man’s ejaculate neutralize the vagina’s acidity so the sperm can live and potentially fertilize an egg). Carraguard® and PRO 2000 have been designed only to kill infectious agents. The makers of BufferGel also hope that it will deactivate viruses and infections such as HIV, HPV, herpes, syphilis and gonorrhea.

Designing the Perfect Microbicide

The “perfect” microbicide would have to be colorless, odorless, inexpensive, safe to use multiple times a day and for long periods of time, work against more than one STD, be available without a prescription, and be completely undetectable. It's a tall order for a single product, but these demands are made for good biological, cultural and logistical reasons.

From a biological standpoint, women are physically more susceptible than men to HIV and other STDs. However, women must rely on their male partners to provide protection from these diseases. In some cultures, women simply do not have the power to insist that male partners use condoms, especially if that partner is her husband. In addition, asking a male partner to use protection is sometimes tantamount to accusing him of HIV infection, or at least infidelity. For these cultural reasons, women must be able to use microbicides without detection.

Many of the women who do not have agency over their sexual lives also live in countries where wages are low and healthcare is spotty at best. Therefore the cost, accessibility, and versatility of microbicides are all important issues.

What We Learned From Nonoxynol-9

Another advancement in microbicide design actually followed from the failure of spermicides in preventing HIV infection. The widely used spermicide nonoxynol-9 initially appeared to prevent HIV and other STDs in laboratory testing, but fell short once it was tested in women. In fact, nonoxynol-9 may actually increase HIV transmission because it causes small disruptions in the vaginal cells that may make it easier for the virus to enter. Among the lessons learned from nonoxynol-9 is that an effective microbicide would have to be easy on the cells in the vagina.

Benefits for Men

Women wouldn’t be the only ones benefiting from the development of microbicides. The Global Campaign for Microbicides also believes that a male would be protected if his female partner has HIV and uses a microbicide. There are also plans for a rectal microbicide (for use in the anus), which will help the gay community, especially men of color who have sex with men. Men of color now account for almost half of new HIV infections among homosexuals.

What’s the Hold Up?

Clinical trials have been underway since the early 90s, but several different factors have conspired to keep an effective microbicide from reaching the market. First, many large pharmaceutical companies do not see microbicides as a profitable product. Without the financial and logistical muscle of Big Pharm, much of the development of microbicides has been left to academic institutions, nonprofit organizations, and small biotech companies.

Second, most research efforts (and much of the money) for HIV/AIDS have been targeted at finding a vaccine. Since vaccines have felled other global killers such as polio and smallpox, they were a natural choice for initial research efforts. However, as repeated failures have stymied vaccine development efforts, investors have begun to look into funding other lines of research.

Currently stalled in subcommittees is the Senate Bill 550, the Microbicides Development Act of 2005 (or HR 3854, as it was introduced to the House of Representatives). If passed, the act will increase the federal budget and commitment to research and development of microbicides. The National Institute of Allergy and Infectious Disease predicted a suitable microbicide could be available to the public in 4-7 years.

Only Half the Battle

Though not nearly as effective as condoms (the first generation of microbicides are estimated to be only 50-60 percent effective), researchers predict that, when added to list of safer sex options, microbicides could avert 2.5 to 3 million HIV infections over a three-year time period. Perhaps just as important, microbicides represent a changing approach in STD prevention. While female-controlled forms of birth control have been around for many years, microbicides are the female-controlled forms of STD protection. While they are not a magic bullet for stopping the HIV/AIDS epidemic, microbicides promise to be an important weapon for women, who have been left unarmed in this battle.