Microbicides to prevent HIV infection
New research may yield tools to block HIV
Today, more than half of new HIV infections occur among women. Based on the latest data from the World Health Organization, HIV/AIDS is the leading cause of death globally in women ages 15 to 44, particularly in sub-Saharan Africa, where the epidemic has hit hardest.
Women are more vulnerable to HIV infection than men, and often they have less power to protect themselves against the virus. An effective microbicide would give both women and men a new tool to guard against HIV and possibly other sexually transmitted infections. For women in the developing world, microbicides may be especially important to survival.
Protecting people from HIV
Microbicides are products that people would use topically to block transmission of HIV and other sexually transmitted infections. Microbicides could come in many forms, including gels used around the time of sex, once-daily gels, films, and vaginal rings that could provide protection for a month or longer. Some multi-purpose products are also under development to prevent unplanned pregnancies as well as HIV and other sexually transmitted infections. Vaginal microbicides would address one of the biggest gaps in the existing continuum of prevention options by offering a discreet method women would use to protect themselves.
The HIV prevention options available today—condoms, abstinence, mutual monogamy, and treatment for sexually transmitted infections—are not feasible for many women, especially those in low-resource settings. In many cases, women don’t have the power to insist on condom use or fidelity, and they may not be able to leave relationships that put them at risk. A vaginal microbicide would not require a partner’s cooperation, putting the power to protect themselves in women’s hands.
Microbicides within reach
After decades of research, there is great reason to believe that safe and effective microbicides are within reach. The latest research shows that microbicides that are based on the same types of antiretroviral drugs (ARVs) already in use to successfully treat HIV/AIDS and to prevent mother-to-child transmission can also offer women protection against HIV. For example, findings from the first clinical trial of an ARV-based microbicide called tenofovir announced in 2010 offered new cause for optimism. The CAPRISA trial demonstrated proof-of-concept that an ARV-based microbicide can prevent women from becoming infected with HIV through sex with a male partner. Additional studies have found that a daily ARV pill taken by people who do not have HIV can reduce their risk of infection significantly.
A number of important studies that seek to understand whether ARV-based prevention can help prevent HIV infection in different populations are in progress. These include:
• The International Partnership for Microbicides (IPM) Ring Study, which is testing a monthly vaginal ring for HIV and pregnancy prevention.
• The Microbicide Trial Network VOICE study, which is testing an oral ARV-based HIV prevention product.
Although these next-generation microbicides have the potential to transform the global response to HIV infection and save millions of lives, the products attract little funding from market-driven sources. For this reason, money for research and development of next-generation microbicides must come in large part from governments and philanthropic donors.
For more information on the above data, see: