To me, this is the most remarkable thing about global health: With a relatively small amount of money, you can do a great deal of good for a great many people. This is money well spent, and we should go back to spending it—now.

We have an opportunity to save more lives around the world than ever before—and I want to do even more to help. That's why I'm giving away virtually all of my wealth through the Gates Foundation over the next 20 years.