Big, encouraging news on the HIV prevention front: This week, not one but two major studies involving heterosexual women and men found that by taking a daily dose of HIV meds, uninfected folks can dramatically reduce their risk of contracting the virus from their HIV positive partner.

While researchers continue work on a vaccine and female-controlled prevention tools like vaginal microbicides, this latest development in so-called pre-exposure prophylaxis represents another option for heterosexual women of color who continue to be disproportionately affected by HIV.

The first of the two studies involved committed couples in which one partner had HIV and the other didn’t. Led by the University of Washington’s International Clinical Research Center and funded by the Bill and Melinda Gates Foundation, the study, dubbed Partner PrEP, provided 4,758 serodiscordant duos in Kenya and Uganda with what it describes as a comprehensive package of HIV prevention services. This included intensive individual and couples’ safe sex counseling, HIV testing, free condoms, testing and treatment for other STDs, and monitoring and care for those with HIV.

One third of the HIV-negative folks were randomly selected to receive the HIV-fighting drug tenofovir (also known as TDF or by its brand name Viread). One third got tenofovir disoproxil fumarate emtricitabine (a.k.a FTC/TDF or Truvada). The remainder took a placebo. The study was double blind, meaning neither the participants nor the doctors who interacted with them knew who was taking the meds and who had the placebo. The results according to this Washington University press release:

A total of 78 HIV infections occurred in the study: 18 among those assigned TDF, 13 among those assigned to FTC/TDF, and 47 among those assigned placebo. Thus, those who received TDF had an average of 62 percent fewer HIV infections … and those who received FTC/TDF had 73 percent fewer HIV infections than those who received placebo.

The second study, led by the U.S. Centers for Disease Control and Prevention (CDC) and the Botswana Ministry of Health (and wonkily called TDF2) involved 1,219 uninfected women and men ages 18 to 39. Some were randomly assigned FTC/TDF, the generic version of Truvada; others had the placebo. All participants in the Botswana-based study received 360-degree HIV prevention services.

Of the 601 people who got the HIV meds, nine got the virus during the study; among the 599 on the placebo, 24 contracted HIV. (Both groups will receive treatment). In short, HIV negative women and men on meds were 63 percent less likely to get infected during the study.

As tempting as it is for us to think, "Hey, I can just take a pill now!" it’s important to remember that both studies provided intensive sexual health education and testing, regular medical exams, free condoms and what experts call "adherence counseling" and regular people call nudging someone to take their meds every single day. The studies also helped participants who had annoying side effects such as nausea, weight loss, headaches and rashes cope with them.

Still, these results are a big deal. Until there’s a cure and a vaccine–and we continue to demand them, Big Pharma-that-stands-to-make-a-handsome-profit-from-more-folks-on-meds–we have another way to protect ourselves. Given the well documented, staggering infection rates, which I won’t depress you with here, we need all the help we can get.