Microbicides: progress in Development of a Novel Approach to the Prevention of HIV/STD

FHI USA

Microbicides represent a novel approach to HIV and STD prevention, but more resources for research are still need according to Dr Kenneth Mayer, Director of Brown University AIDS program. Microbicides are chemical barriers applied topically to genital mucosal surfaces (vaginal and rectal) to prevent the transmission of HIV and STI pathogens. Clinical trials of several candidates for microbicides are currently under way. Research is focusing on microbicides that could either kill the HIV and/or other STI pathogens, prevent HIV from binding to target cells, or boost the vagina's natural defence mechanisms. Some research is exploring anti-retroviral drugs for their applications as topical microbicides. The argument for increasing prevention option is compelling - as the UNAIDS study indicates that 47 percent of new HIV infections occurred in women during 2000, mostly through sexual transmission.

Dr Peter Kilmarx, from the Centre for Disease Control and Prevention in Thailand, said that a study in Chiang Rai (Thailand) showed that 76 percent of new HIV infections occurred in married women who never had a casual partner. Dr Suniti Solomon, from YRG CARE, Chennai, India, presented a cohort study stating that 88 percent of housewives responded that they couldn't ask their husbands to use condoms. This emphasises the need to have microbicides as a prevention option for women who cannot get their partners to use the existing prevention options including male condoms. Despite the urgent need, there are two major barriers in making safe and effective microbicides widely available. One is lack of resources for research, especially for large-scale Phase III Clinical trials. Many promising products cannot advance to efficacy trials because of inadequate funding from public sources. The second barrier concerns the question whether the women will use microbicides in Asia. Among housewives in the YRG CARE study (Chennai India), 96.7 percent of respondents said that they have never applied any medication in the vagina, though 45 percent housewives responded that they would use products like microbicides if they were available.