https://www.coursera.org/learn/communicating-during-global-emergencies
It seems like Emory is offering it for free, with a new suite of students starting each week. It's nothing that mindblowing, just a three week course. The focus is more on communicating with the public, though it might be useful for communicating with journalists.
I'm one week in. The 'textbook,' such as it is, is a free (I think?) PDF from the CDC that walks through a recommended philosophy of CERC - Crisis and Emergency Risk Communication. Basically,
- Be First.
- Be Right.
- Be Credible.
- Express Empathy.
- Promote Action.
- Show Respect.
You want to make sure you communicate quickly, so folks don't start looking for less-reputable sources. You want to tell the truth, and be honest about what you don't know and what you're doing to fill in the gaps.
Don't lie or mislead to try to calm people. Give them recommendations for things they can do so they can try to have some sense of control. (And be active - "Boil your water" - rather than restrictive - "Don't drink tainted water.")
Make sure people trust that you care about them, and that you don't look down on them. You might have to ask them to do things that suck for them but help the greater good, and they need to believe you have their best interests at heart.