2000 ANNUAL REPORT
Microbicides: Protecting women from sexually transmitted infections
Women often have little ability to protect themselves from sexually transmitted infections by negotiating condom use or ensuring mutual monogamy. Therefore, the Population Council is committed to developing vaginal microbicides, products that women could use to avoid contracting sexually transmitted infections, including HIV. The Council’s lead candidate microbicide, Carraguard™, is a carrageenan-based gel developed by scientists at the Center for Biomedical Research. In 2000, researchers in the Council’s International Programs Division began conducting, and nearly completed enrollment for, expanded safety and acceptability trials of Carraguard among women in South Africa and Thailand, in collaboration with institutions in both countries.
The development of Carraguard was preceded by investigations into how HIV enters the body from the vagina and how this entry can be blocked. Carrageenan, a product derived from seaweed, has been used for decades in food and cosmetic products. Council studies have shown that carrageenan is safe and acceptable when used vaginally. Carraguard protects against HIV, herpes simplex virus 2, human papillomavirus, and gonorrhea in cell culture and animal models and retains activity for several hours after application. “HIV doesn’t infect mice, but it does pass through their vaginal epithelium. Carraguard blocks this passage,” explains biomedical researcher David M. Phillips. Trials to determine the gel’s effectiveness in humans will begin after the current safety and acceptability trials are finished in 2001.
Council scientists have begun assembling the preclinical file required for obtaining U.S. Food and Drug Administration approval to begin effectiveness trials. Additionally, they continued to investigate ways to broaden the spectrum of pathogens potentially blocked by Carraguard, to extend the length of time that it remains active, and to add other ingredients to make a version that also protects women against unwanted pregnancy.
Council researchers began preparing for ancillary microbicides trials that will include studies of the safety and acceptability of Carraguard in HIV-positive women and men. In South Africa, in preparation for expanded safety trials of the microbicide, Council researchers evaluated the process of obtaining informed consent. Also in South Africa, researchers plan to determine whether there are methods of testing for sexually transmitted infections that are less invasive, more acceptable, and more feasible than methods that require pelvic examinations. In Thailand, Council researchers will study the safety and acceptability of Carraguard in HIV-negative couples.
In addition to developing and testing a microbicide, Population Council researchers endeavor to raise awareness about microbicides among government officials, activists, scientists, public health workers, and donors. To that end, Council staff members made presentations at Microbicides 2000, the first-ever global conference on topical microbicides, in March. Council researchers also co-sponsored a technical consultation on microbicides in London in April. Experts there identified key policy constraints, developed strategies to address them, and reviewed and commented on The Case for Microbicides: A Global Priority, a booklet intended to answer questions about and raise the profile of microbicides. In July, Council researchers co-hosted a meeting at the XIIIth AIDS Conference in Durban, South Africa to introduce The Case for Microbicides and highlight some of the issues it explores.
