These vaccines hold promise. But before we go ahead with a recommendation for global vaccination, we will first need to know how well these vaccines work in developing parts of the world.

We've been involved in a number of settings where because of the lack of info, rumors get spread, misinformation becomes a real problem.

I think of it as the earthquake in San Francisco. You know it's on the fault. You know it's going to occur, but you can't tell if it's going to occur this year or next year or the year after.

This is certainly a big step forward. A big and an exciting step forward.

Children in the developing world may respond differently.

She will definitely need to be in a wheelchair.