Microbicides are products being developed to reduce the spread of HIV and other sexually-transmitted diseases (STDs). Microbicides could come in many forms, including gels, creams, suppositories, films, lubricants, sponges, or vaginal rings. They could be used in the vagina or rectum.

Microbicides could work in different ways:

1. Killing or making inactive germs such as bacteria and viruses
2. Changing the chemistry of a woman's vagina to make infection less likely
3. Blocking infection by creating a barrier between the germ and the cells of the vagina or rectum
4. Preventing the germ from multiplying after it has entered the body

No. Scientists are testing many products to see whether they help protect against infection with HIV and/or other STDs. Some of these products have proven safe enough in lab studies that they are now being tested in people. However, no safe and effective microbicide is currently available to the public.

Microbicides have been in development for the past 15 years. A number of studies conducted on the early products have so far failed to find an effective microbicide.

However, there is hope that a new group of microbicides that contain HIV drugs will be more effective. Unlike earlier products, these newer microbicides do not have to be applied at the time of sex. They may be used daily as a gel and or in the form of a vaginal ring, that might only need to be inserted once a month.

Promising results were reported in July 2010 from a large study called CAPRISA 004. This study showed that women who used a 1 percent gel version of the HIV drug Viread (tenofovir) inside the vagina had 39 percent fewer HIV infections. These findings provide early proof that HIV drug-based microbicides, in particular tenofovir gel, can help protect women against HIV. (See http://www.mtnstopshiv.org/node/2005 for details of this trial).

The CAPRISA 004 study also showed that the tenofovir 1 percent gel had a 51 percent protective effect against herpes simplex virus (HSV-2), or genital herpes. This is important because people infected with HSV-2 are more likely to get and transmit HIV.

At this point, the gel version of tenofovir is not available (and there is no information on the use of the tenofovir pill inside the vagina). Further research is needed before a microbicide will be approved for use by the public. A number of studies looking at tenofovir, as well as other drugs that target HIV, are in progress.

No. When used consistently and correctly, male or female condoms are likely to provide better protection against HIV and other STDs than microbicides, so they will still be the best choice. But for people who cannot or will not use condoms, microbicides would provide another option. This is especially true for women whose male partners refuse to use condoms. Using microbicides could save lives and have a major impact in reducing the spread of HIV.

Many of the microbicides being tested work against HIV and at least one other STD. In time, a product that combines different microbicides might be developed that could prevent a wide range of STDs, including HIV.

Some of the microbicides being studied would allow a woman to get pregnant. These are called non-contraceptive microbicides. They would offer women the option of getting pregnant while still protecting themselves from infection – an option that is not available with condom use. The tenofovir 1 percent gel tested in the CAPRISA 004 study and mentioned above is one example of a non-contraceptive microbicide. Contraceptive microbicides would prevent pregnancy and STDs. It is important to have both types available.

Any new product must go through strict safety testing before becoming available to the public. Health activists and researchers are closely watching over the clinical testing of microbicides to make sure it is done correctly.

It is possible that an HIV+ woman’s male partner might be protected from infection if she used a vaginal microbicide. However, this would need to be tested in clinical trials. Microbicides may work if they are used rectally, but the safety and effectiveness of microbicides for rectal use must also be tested separately in clinical trials. Rectal safety studies of some products have started.

Microbicides could help protect HIV+ women from re-infection with other HIV strains and from other STDs.

Research on developing a vaccine to prevent HIV infection has not been successful so far. Microbicides may be available sooner than an HIV vaccine. Even if a safe and effective vaccine is discovered, vaccines and microbicides will both have roles to play in the prevention of HIV.

Advocates are working with researchers and policy makers to make sure that any approved microbicide will be as affordable and accessible as possible.

N-9 products are sold over the counter as spermicides that can prevent pregnancy. They cannot prevent the transmission of HIV or other infections. In fact, when used more than once a day, N-9 contraceptive products may actually increase HIV risk by irritating the skin of the vagina. Other studies show that N-9 is even more irritating to the rectum than to the vagina.

According to the World Health Organization (WHO):

• N-9 is not effective at preventing the transmission of HIV or other STDs. It should NOT be used for disease prevention.
• Women at risk for HIV, especially those having sex more than once a day, should NOT use N-9 for birth control
• Women who are not at risk for HIV can use N-9 for birth control purposes safely
• Condoms with N-9 provide no more protection against pregnancy or infection than plain lubricated condoms. Since N-9 condoms may cause irritation, they should not be used.
• Products with N-9 should NEVER be used for anal sex

Until microbicides are available, the best way to protect yourself and your partner from STDs, including HIV, is by using a male or female condom. It is also important to avoid the use of nonoxynol-9 (N-9) products if you think there is any chance you may be exposed to HIV. Getting tested for STDs regularly and getting treatment promptly if you have an STD will also help reduce your risk of HIV infection if you are exposed to HIV.