This week, I am in Rome, Italy, for the International AIDS Society's Conference on HIV Pathogenesis, Treatment, and Prevention. This gathering of researchers caps a year of incredible scientific announcements, and I anticipate even more at this meeting.
Last summer, the PEPFAR-funded CAPRISA study of a tenofovir-based microbicide demonstrated successful proof-of-concept for this female controlled prevention method. The study showed that women using the microbicide gel had an average of 39 percent fewer HIV infections and 51 percent fewer genital herpes infections compared to women who used a placebo gel. The results of this study were clear evidence of the importance of U.S. investments -- across multiple agencies -- in microbicides. And through PEPFAR, our country teams will be working to create the regulatory path and client demand for these products when they are ready to be marketed, so that this innovation can be quickly brought to bear in order to save lives.
In May, a National Institute of Health (NIH) randomized control trial confirmed earlier observational evidence and clearly documented that treatment also worked as an extraordinarily effective tool for the prevention of sexual HIV transmission. Initiation of antiretroviral treatment (ART) by HIV-infected individuals substantially protected their HIV-uninfected sexual partners from acquiring HIV, with an astonishing 96 percent reduction in risk of HIV transmission. By lowering the viral load of HIV, ART greatly reduces the risk of sexual transmission of HIV to an uninfected partner.
And just this week, two studies have confirmed an initial proof-of-concept trial demonstrating the use of pre-exposure prophylaxis (PrEP) against HIV infection. In these studies, individuals taking a daily tenofivor or tenofovir/ emtricitabine combination experienced infection rates more than 60 percent lower than those on a placebo. This finding further advances potential options in prevention for couples where one partner is infected with HIV and for other high-risk populations.
I expect additional innovations to be announced at this meeting, creating momentum around “what's possible” in fighting HIV/AIDS. Nearly a decade after the creation of PEPFAR and the Global Fund helped begin to restore hope to hard-hit nations, these new research achievements are bringing a second wave of hope to communities impacted by AIDS. They are creating a mood of optimism and promise as we turn our attention to next year's International AIDS Society meeting in Washington, D.C.
Many of these advances have benefited from the funding and expertise found throughout the U.S. government. They have the potential to radically change the way we think about HIV/AIDS in the developing world, and help to prevent millions of new infections worldwide. We will work with the World Health Organization and others as they develop the normative guidance that will allow us to partner with countries to translate these scientific findings into effective, lifesaving programs.
In order for us to fulfill the promise of these findings, we will continue to foster shared responsibility among all parties. We will continue to work with our partners in national and local governments, enabling them to create the policies and systems that allow innovations to be rapidly implemented and scaled up at the country level. We need to work with ministries of finance and other donors to coordinate and complement financing, so that we get the maximum life-saving impact for every dollar spent. And we will continue to make sure that these efforts build upon and help to strengthen the health systems that deliver care in the developing world.
It's a tall order, but I believe we can achieve amazing things over the next few years. I am honored to lead a program that is at the forefront of putting scientific advances into practice to save lives, and look forward to reporting back from Rome.