What are Microbicides?
The term “microbicide” refers to a range of experimental products such as gels, creams, rings, and films that aim to prevent the sexual transmission of HIV. Current microbicide trials are evaluating candidates that are applied vaginally or rectally using an applicator. In most of these studies volunteers are asked to use the candidate microbicide before, and sometimes after, every sex act. There is also work underway to explore other types of “delivery” systems, such as a vaginal ring that would release the microbicide that could be worn for long periods of time and wouldn’t require application before sex.
An effective microbicide would reduce the risk of HIV infection at the site of sexual exposure. There is a range of ways that a microbicide might provide this protection. It might contain an active ingredient that blocks HIV activity directly; it might provide a more general enhancement of naturally-occurring mucosal defenses and/or physical barrier at the mucosal surfaces.
Global investment in microbicide R&D fell in 2013 by US$35 million, to a total of US$210 million. Of that 2013 total, the public sector provided US$187 million (89 percent), the philanthropic sector provided US$20 million (10 percent) and the commercial sector gave US$3 million (one percent). Funding decreased in all sectors in 2013, with the largest reductions in funding coming from US public-sector agencies, whose participation fell by US$18 million in 2013, due largely to substantial reductions in NIH and USAID funding. Still, the US public sector remained the largest source of microbicide investment overall, funding 74 percent of the 2013 total.
The philanthropic sector also reduced its funding in 2013, with the largest philanthropic funder, BMGF, decreasing funding by nearly US$4 million. Additionally, some philanthropic funders that had invested in microbicide research in previous years did not do so in 2013.