>There will certainly be a lot of interesting studies after this is all over comparing mitigation measures - at the moment it is not so clear which ones work, and at which stage in outbreaks they are most useful.

So many variables. I wonder how clear things will become even in hindsight. Of course, it doesn't keep people today from being very certain and very dogmatic and very strident today about the right things to do on Twitter, Facebook, and elsewhere.