We are calling this an epidemic, not just an outbreak.

The vaccine is working. The vaccine certainly was made to cover this particular strain because it's a fairly common strain of mumps.

We're not ever going to know, I don't think, exactly why the epidemic in Uganda got better, ... What we know is that there was a lot of intensive effort early in the epidemic and I think the message for Uganda remains. ... Please continue to do all those things that we know are effective in preventing the infection.

370,000 in one outbreak to be destroyed is really, really big. This is not a good signal.

The Ebola epidemic was the most frightening outbreak I have witnessed in my lifetime, and I believe it was necessary to react globally as strongly as we did.

There is no firm dividing line between what is an epidemic and what is not an epidemic, but I think, when you look at a map that shows widespread influenza activity in 36 states, that we regard it -- from a common-sense perspective -- as an epidemic.