The term "microbicide" was coined to define a variety of products such as gels, creams, films or suppositories that, when inserted into the vagina or rectum prior to sexual intercourse, might prevent HIV transmission during intercourse. This concept was initially developed specifically as a female-controlled method (vaginal application) to prevent sexual transmission through heterosexual intercourse. As a result, the term has achieved a certain brand recognition as a method primarily intended for use by women. However, safe and effective compounds can also serve as an important prevention tool for men who have sex with men (rectal application).
But, translating these hopes into science has proven to be a challenging task, requiring focused tenacity over three decades, coming in three waves:
- The first wave of trials focused on nonoxynol-9 (N-9), which had a half-century track record of being used safely as a spermicide. Moreover, N-9 gel appeared to be effective against HIV in the test tube and was available over the counter. In the 1980s, observational data on N-9 gel against both sexually transmitted infections (STIs) and HIV were encouraging. Randomized trials in the 1990s, however, found N-9 to be ineffective in preventing HIV and other STIs.
- The second wave of studies to evaluate products featured other nonspecific agents (against HIV), such as vaginal defense enhancers, other surfactants and entry/fusion inhibitors. Several of these products, including Savvy (1 percent C31G), UsherCell (6 percent cellulose sulphate), 2 percent Pro2000 and Carraguard were evaluated in phase III trials, all with disappointing results.
- But the third wave was the charm. Using antiretroviral (ARV) drugs in a gel form provided encouraging results. In 2010, South African investigators found that women using the ARV gel before and after sex were protected from acquiring HIV. The key was, like anything in life, that this gel product had to be used to be effective. Indeed, a trial known as VOICE found this same gel was not effective among women who were asked to use it daily. Further studies are under way both to confirm the results of the first trial -- the gel used before and after sex -- and to evaluate more convenient ways to deliver ARVs.
Buoyed by the successful trial, public health practitioners turned to ways to market the product. Although microbicide products are not yet available, preparing ourselves sooner rather than later will give us a head start. We know that making microbicides widely available for HIV prevention, both globally and in local contexts, will require a comprehensive approach, including:
- Knowledge of recent research results
- Up-to-date policies and guidelines
- Effective communication and marketing
- Quality training, supervision and services
- Appropriate logistics
Our colleagues at FHI 360, together with our partners from the K4Health project at the Johns Hopkins Bloomberg School of Public Health's Center for Communication Programs (JHU CCP), have developed a toolkit providing information about microbicides for health policymakers, program managers, community educators, trainers, advocates and communication specialists. This toolkit is designed to facilitate implementation strategies for microbicide products once they hit the marketplace. The toolkit provides resources under the thematic categories of essential knowledge, clinical research, implementation research, policy and guidelines, advocacy and communication, training and country experiences.
In conclusion, the measurable progress we have been made in developing a safe, effective microbicide is a tribute to the tenacity of advocates and scientists alike. It has allowed us to prepare a toolkit so we're ready to hit the ground running when the first product becomes available to the public. Tenacity and toolkits, indeed.
Ward Cates is the President Emeritus, FHI 360 in Research Triangle Park
Laura Raney is the Senior Technical Officer, FHI 360