There were a lot of missteps in the early days, but because we got in early we got to make more mistakes than other people.

The tool that's most associated with the recent progress against malaria is the long-lasting bed net. Bed nets are a fantastic innovation. But we can do even better. We can invent new ways to control the mosquitoes that carry the malaria parasite.

Even in some of our vaccine areas, like an AIDS vaccine, things have taken longer than we expected, but we have the pipeline of tools. The biological information that we have that gives us insights is fantastic.

India just went 3 years with no cases [of polio]. Pakistan is our toughest location right now because some parts of the Taliban have not allowed vaccinators to come in and have even attacked vaccinators. We are hopeful this will get resolved since no one wants their kid to be paralyzed. I spend a lot of time making sure the polio campaign is doing the best it can. We have great computer models that help guide our activities.

The UK is a very international country.

Certainly I'll never be able to put myself in the situation that people growing up in the less developed countries are in. I've gotten a bit of a sense of it by being out there and meeting people and talking with them.

We all need people who will give us feedback. That's how we improve.