amfAR, The Foundation for AIDS Research

New Report Highlights Importance of Rectal Microbicides

May 3, 2002—Researchers, public health experts, and advocates gathered in Antwerp, Belgium, May 12-15, for Microbicides 2002, the second international conference intended to focus attention on the critical role that microbicides could play in slowing the global spread of HIV/AIDS. The first meeting in Washington, D.C., in May 2000 was also co-sponsored by amfAR.

Synthetic or natural substances formulated as a gel, cream, suppository, or film, microbicides would either inactivate or kill HIV, physically block its attachment to susceptible target cells, strengthen natural immune defenses, or prevent HIV's spread from infected cells. A microbicide could also neutralize other sexually transmitted diseases that often facilitate HIV infection.

Over the past few years, vaginal microbicides have gained increasing attention because many women lack the power to avoid sex with men who may be HIV-infected or to insist on condom use. Unlike other barrier methods such as condoms, microbicides could be used without the cooperation or even the knowledge of one's sexual partner.

But many men who have sex with men (MSM) also experience problems ensuring that their sexual partner uses a condom, and the Microbicides 2002 conference included several sessions on rectal microbicides. A new amfAR-published report on creating a research and development agenda for rectal microbicides that can protect against HIV infection was available at the Antwerp meeting.

One Columbia University study found that 43 percent of MSM surveyed reported inconsistent condom use, and 92 percent expressed interest in using a rectal microbicide if one were available to prevent HIV. Of course, a rectal microbicide would also benefit women. The largest-ever survey of sexual behavior among Americans found that eight percent practice anal sex at least occasionally. And the rate of female anal intercourse is likely even higher in societies where the practice is used as a method of preserving virginity and avoiding pregnancy.

The new report from amfAR includes presentations from a June 2001 workshop organized by the HIV Prevention Trials Network with the support of the National Institute of Allergy and Infectious Diseases and the National Institutes of Health, Office of AIDS Research, which sought to:

  • Establish the current knowledge base relevant to rectal microbicide research and development;
  • Identify the biomedical and behavioral research needed to advance our understanding of the potential role of microbicides in preventing rectal HIV infection;
  • Outline key considerations related to product acceptability, including applicator design; and
  • Propose an appropriate clinical development strategy for rectal microbicides.