Even for the diseases we don't focus on, cancer, heart disease, you're going to be way better off being sick 10 years from now than any time in the past.

When Paul Allen and I started Microsoft over 30 years ago, we had big dreams about software. We had dreams about the impact it could have.

AIDS itself is subject to incredible stigma.

Understanding science and pushing the boundaries of science is what makes me immensely satisfied.

It is hard to sell Congress and the American people on foreign aid. Is it harder to do that than it is to sell billionaires on the idea that they should give all their money away.

Going out in the field, it's always enlightening to see what's working and what's not and to sit down and talk - I was with young girls in south Africa - understanding why our tools for prevention aren't being adopted, and what way may need to invent to help protect them.

When you say that after World War I there was a pandemic that killed more people than the war itself, most will say: "Wait, are you kidding? I know World War I, but there was no World War 1.5, was there?" But people were traveling around after the war, and that meant the force of infection was much higher. And the problem is that the rate of travel back then was dramatically less than what we have nowadays.