June 29, 2007
They could be a very important part of global HIV prevention efforts. Currently, male and female condoms are the only tools we have for HIV prevention. However, many men object to wearing condoms. Many women do not feel they can demand, or even ask their male partners to use a condom. Currently, over 50% of new HIV infections worldwide occur in women.
The use of microbicides could be controlled by women. They could be applied before sex. They won't require male cooperation to use, the way male and female condoms do. Some might be products women can use without their partners' knowledge.
They will come in gels, foams, and creams. Some may take the form of a sponge or thin film that can be inserted with the fingers. Rings or diaphragms may also be inserted into the vagina to deliver microbicides. Microbicides can also be put in suppositories, small plugs of medication designed to melt at body temperature when placed in the vagina or rectum.
One study estimated that microbicide use could prevent about 2.5 million HIV infections within 3 years. This is based on a microbicide that only worked 60% of the time and was used by only 20% of women, in 73 low income countries. Microbicides may also protect women against some other sexually transmitted diseases, in addition to HIV.
Condoms are still the most effective method of preventing infection. Ideally, microbicides would be used along with condoms for added protection. But, for people whose partners won't use condoms, microbicides could offer a way of reducing HIV risk that can be used without a partner's participation.
Microbicides, on the other hand, depend on people remembering to use them correctly each time they have sex. Once developed, microbicides and vaccines would work together. Microbicides will put the power of prevention directly in women's hands.
After a period of optimism about the development of an HIV vaccine, research has slowed. The virus presents several obstacles to vaccine development. At this point it is not clear when a vaccine might become available. However, it is unlikely to be within the next 10 years.
Microbicide research is further along. But microbicide research has also encountered setbacks. Nonoxynol-9 (N-9) is a spermicide that was tested as a microbicide. Research showed that frequent use of N-9 may actually increase the risk of HIV infection. It can damage the lining of the vagina or rectum, making it easier for HIV to get past the body's defenses. N-9 had to be discarded from the list of potential microbicides.
Four microbicides are in Phase III (final) testing. See Fact Sheet 105 for more information on the clinical testing process. The microbicides closest to approval are Carraguard, PRO 2000 Gel, BufferGel and Savvy. Cellulose sulfate gel is also being studied as a contraceptive. Studies of cellulose sulfate gel (Ushercell) were stopped in 2007.
Dozens of potential microbicides are in various stages of research. Once available, they could help women and men protect themselves. Microbicides may be especially important for women in developing nations who are not always empowered to require partners to wear condoms.
The Global Campaign for Microbicides (www.global-campaign.org) provides information about global microbicide advocacy efforts. It explains how people can become involved in making microbicides a reality as soon as possible.