Microbicides for Prevention Research
Overview
The HPTN's microbicide agenda is transitioning to the Microbicide Trials Network (MTN). Information on current HPTN microbicide trials will be maintained on the HPTN website until this transition process is complete.
Microbicides are antimicrobial products formulated for application to the surface of the vagina and/or rectum for the prevention of HIV transmission during sexual intercourse. They are considered to be one of the most promising preventive interventions to emerge over the past decade.
There are several mechanisms of action that may allow microbicides to prevent HIV transmission. These are:
- killing or inactivating pathogens
- strengthening the body's normal defenses
- blocking infection by creating a barrier between the pathogen and target cells
- preventing infection from spreading to other cells
More than 60 products have been evaluated as potential microbicide candidates. The majority of these products have undergone preclinical evaluation, some have advanced into human studies. To be successful in reducing HIV transmission the ideal topical microbicide must have several characteristics:
- it must be safe and effective
- inexpensive and widely accepted
- available in both spermicidal and non-spermicidal formulations
- able to be used without partner knowledge.
Even a partially effective microbicide might have a profound impact on the dynamics of HIV transmission. In fact, researchers have developed a mathematical model that shows that if even a small proportion of women in lower income countries using a 60% efficacious microbicide in half the sexual encounters where condoms are not used, could avert 2.5 million HIV infections over 3 years.
