Let me cut to the chase. There’s a program that has helped save the lives of 17 million people in poor countries since 2002. It’s called the Global Fund to Fight AIDS, TB, and Malaria. It’s poised to do even more good in the years ahead, but to continue its work, it needs donors to make new funding pledges.

I just got back from Europe, which is starting to think through many tough decisions surrounding Brexit. Despite that challenge, the governments of France and Italy became the latest to make commitments to the Global Fund, building on recent pledges from Japan, Canada, the United States, and the European Commission. When I was in London, a senior member of the British government confirmed to Parliament that they remain committed to the Global Fund’s success. Although I’m confident the Global Fund will raise the money it needs—donors have consistently recognized that it’s an effective and low-cost way to save lives—we are not there yet.

Since the Global Fund started, Melinda and I have committed $1.6 billion to it. Here are four reasons why we are such big believers:

• Saving lives. In countries where the Global Fund operates, deaths from HIV, TB, and malaria have dropped by a third since 2002. Certainly the Fund doesn’t deserve sole credit for that phenomenal progress, but it has played an irreplaceable role. And its work is far from finished: Three million people still die every year from these diseases.
• Getting rid of diseases so we never have to fight them again. In my lifetime I expect to see the end of malaria, which kills nearly half a million children every year. When you eradicate a disease, you not only save lives, you free up billions of dollars and many hours of effort. One reason I’m so optimistic about ending malaria is the work of the Global Fund, which has slowed the spread of the disease and saved lives by distributing hundreds of millions of bed nets.
• Helping poor countries become more self-sufficient. If you ever hear people say “poor countries just keep getting foreign aid forever,” tell them about the Global Fund. It helps the countries it works with improve their health systems so they can take better care of their people. They also devote an increasing share of their own budgets to health (they have promised to spend 50 percent more between 2015 and 2017 than they did in the previous three years). That translates into less spending by rich governments.
• Using aid efficiently. The Fund has a done a great job keeping costs low and streamlining its work. Its operating costs are just over 2 percent of all the grants it gives out. That means the vast majority of the money that flows through the Global Fund is reaching the people who need it most.

The Global Fund raises money in three-year batches; the current batch will cover the years 2017-19. They’re asking for $13 billion, which will go toward delivering lifesaving drugs and bed nets as well as developing new tools like better diagnostics and next-generation prevention techniques. To put that number in context, it’s about 3 percent of the total foreign aid that rich countries give over three years. And consider the payoff: By one estimate, the $13 billion raised by the Global Fund will generate about $300 billion in economic benefits.

It is never easy to raise large sums of money like this, and it certainly isn’t easy now, with the refugee crisis in Europe compounding an already difficult global economy. Although I don’t think anyone would argue that fighting disease will directly end wars or stop the flow of refugees, improving health certainly makes countries more stable and more prosperous—and less likely to spread disease and instability to their neighbors.

If you want to save and improve lives, health is one of the most effective investments you can make. And if you want to improve health, the Global Fund is one of the most effective investments you can make. It is one of the kindest things people have ever done for one another, and I am inspired by the countries and leaders who are stepping up to support it.