2. I was wrong. Wikipedia shows that the NIAID is part of the NIH. Still a research organization, not a public health organization.
3. Previous outbreaks, such as Ebola, SARS, MERS, etc. have _all_ been spearheaded by the CDC. The CDC is the branch of government responsible for managing disease outbreaks. The CDC head is therefore the "top public health communicator." It's worth noting that being a "communicator" here is much more than about talking to the public; it's also about who talks to the politicians.