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.

Sometimes we do get taken by surprise. For example, when the Internet came along, we had it as a fifth or sixth priority.

I think of myself as a global citizen.

In fact, that's where my vision of the coming digital opportunity is somewhat different from other people's. I divide it into three parts. One is the office. That's the one I'm most excited about and is the most concrete.

Inspiration starts somewhere.

Capitalism has shortfalls. It doesn't necessarily take care of the poor, and it underfunds innovation, so we have to offset that.

We're creating this alliance, GAVI, that has helped buy the vaccines that were in the rich world but not getting to the poor kids, getting a very cheap price and figuring out the cold chain, getting the delivery right, and then funding research for new vaccines. A lot of them are coming along. We've got a meningitis vaccine out, got that through large parts of Africa. That has been a huge success.