Florence Daka is a healthy mother of four who lives in Lusaka, Zambia. She sees her children off to school every morning and works a full day cleaning offices.

That may not sound extraordinary, but it is. It’s extraordinary because Florence is alive and well and living with HIV, thanks to the effective treatment that she takes. What’s more, the medicines that Florence received during her last pregnancy helped her avoid transmitting HIV to her youngest son, Stephen, who is now a healthy two-year-old.

When I met Florence during a visit to Zambia earlier this year, I was struck by her story and how she and Stephen are living proof of the tremendous progress that we’ve made in the fight against AIDS.

A decade ago, almost no one in Africa was receiving drugs to treat HIV. AIDS was a death sentence. Now more than 8 million people in developing countries, the majority of them in Africa, have access to life-saving treatment. The cost of HIV drugs in Africa has plummeted by more than 99%, and most pregnant African women who are infected with HIV now have access to treatment to prevent mother-to-child transmission of the virus.

It’s important to celebrate this tremendous progress – progress that seemed unimaginable just a decade ago – and to stay committed to the fight against HIV. That’s why I joined government leaders, philanthropists, faith leaders, entrepreneurs and entertainers at the Kennedy Center’s Eisenhower Theatre last night to recognize what the world has achieved in turning the tide on AIDS.

This week, the International AIDS Conference will be held in the United States for the first time in more than 20 years. And last night’s Kennedy Center event – with 1,000 global health advocates in attendance – offered a great stage to share success stories and talk about the importance of sustained HIV funding.

I talked about the strong leadership that the President’s Emergency Plan for AIDS Relief (PEPFAR); the Global Fund to Fight AIDS, Tuberculosis and Malaria; and developing country governments have taken to expand access to treatment and prevention.

I also thanked public and private sector leaders in the U.S. for maintaining America’s long-standing commitment to HIV research and development (R&D). Our country still provides 70 percent of all funding for HIV R&D, including efforts to develop more effective and longer-lasting prevention methods and an HIV vaccine. Americans can be justifiably proud of the tremendous moral leadership that the U.S. has taken in producing breakthrough innovations in the fight against HIV.

But America isn’t in this effort alone. I’ve been honored to meet people around the world who are committed to funding and leading critical R&D activities. And I have told them that the Bill & Melinda Gates Foundation is committed to working with partners everywhere to accelerate the discovery and development of new tools to treat and prevent HIV.

Tomorrow, I will be part of a panel at the International AIDS Conference that will discuss what’s needed to sustain progress against HIV in tough economic times. I look forward to sharing my ideas in a follow-up post.