MILES O’BRIEN: Other disease modelers were equally alarmed. At Northeastern University, Alessandro Vespignani also created an Ebola epidemic model at his Laboratory for the Modeling of Biological and Socio-Technical Systems. It predicted that, if nothing was done, Ebola would spread way beyond West Africa.

ALESSANDRO VESPIGNANI, Northeastern University: And you will see that, by February, already, you get Africa that is in a very bad situation, but then you start to have places which have serious outbreaks in various places in Europe.

MILES O’BRIEN: Paris, London and New York would have all been coping with serious Ebola outbreaks.

ALESSANDRO VESPIGNANI: This is something that would be really a worst-case scenario. So that would be something that you don’t even want to think about it.

MILES O’BRIEN: Wow. That’s many millions of people afflicted, right?

ALESSANDRO VESPIGNANI: That would be obviously something that of — well, unthinkable.