The argument for optimism has some awfully good evidence in Rwanda. A quarter-century after a genocide tore the already poor East African country apart, Rwanda is a case study in what’s possible. Led by physician Agnes ¬Binagwaho, the nation’s former health minister, and others, Rwanda has steadily invested in health infrastructure, primary care, massive childhood vaccination, and maternal health.
Groups like the Gates Foundation, GAVI, The Global Fund, and Partners in Health—cofounded by Paul Farmer, who lived in Rwanda for years—have financed the effort substantially. But much of the innovation and footwork has been homegrown. Child mortality, meanwhile, has dropped from one of the highest rates in sub-Saharan Africa to one of the lowest.
The turnaround is so extraordinary that Farmer, a Harvard professor of global health and social medicine and a celebrated pioneer in treating tuberculosis, has launched an academic center to study it: the University of Global Health Equity. (Binagwaho has been named vice chancellor.
“We see it in lots of places: real examples of governments making investments—working with UN agencies, with NGOs, with others, but really driving their own future by investing in their young people,” says Desmond-Hellmann. “It’s happening not just in Rwanda, but also in Ethiopia, Bangladesh, and elsewhere.”
“We have to be able to see the reality of what’s going on in the world … But we [also] have to believe in the world getting better.” – Melinda Gates
But it’s work that has to be sustained, say the Gateses—and virtually every other global health expert. The sobering truth is that Rwanda, like Nigeria, is on a knife’s edge: If efforts to combat malaria, TB, AIDS, and tropical diseases slow or even remain static, the cases of disease don’t stabilize, they go up. And the next generation of kids loses ground.
It’s why the Gateses are so focused now on replenishing contributions for The Global Fund, a triennial fundraising push that takes place in October—and the financial refueling of GAVI after that. These two institutions are the outstretched limbs of the Gates Foundation, and the couple have spent more of their philanthropic dollars supporting health delivery programs like these than anything else.
“They could have elected to do anything with their lives,” says Warren Buffett, “and both of them are not only spending money but huge amounts of their time and energy around the world to make life better for people. Think about that.”
A version of this article appears in the May 2019 issue of Fortune.