Our vision, which has not changed since the day the company was founded.

Teaching's hard! You need different skills: positive reinforcement, keeping students from getting bored, commanding their attention in a certain way.

I never took a day off in my twenties. Not one. And I'm still fanatical, but now I'm a little less fanatical.

We're still missing about a dozen vaccines that will make a huge difference. For adults, we've got HIV and TB are still huge; for kids malaria is still killing a half million kids a year out of that 6 million. We probably need some vaccines, but we need a little more data to make sure we're getting the vaccines that will save the most lives.

We're very enthused about the idea that in the third trimester we actually give the mother a vaccine and her antibodies, the protective things that the immune system makes, actually pass through to the baby, both when the baby is born, and through the mother's milk. Because the baby's immune system is actually not very strong for that first few months, using the mother's immune system to do this - it's a very exciting idea and something that we're investing heavily in.

The best teacher is very interactive.

Part of the magic of economic growth is how you educate people, and the leading economies have to stay in front of that. From an economic point of view, it affects competitiveness and creates jobs. Or from a social justice point of view, you can take someone in the bottom tier of income and let him compete to be a doctor or lawyer. The education system is the only reason the dream of equal opportunity has a chance of being delivered - and we're not running a good education system.