Fundamental question on flattening the curve.
It is not a function of reducing number of infections, just expanding the timeline of those infections correct?
I've heard my states very own head medical officer say that yes she still expects 40-70% of the population to be infected. Over a few weeks that would be pretty terrible, but over 6 months it might be manageable.
Is that not what we are trying to accomplish? Prevention/Eradication is impossible at this point correct?
I think different people are trying to do different things, and that's part of what's getting us in trouble and creating confusion.
From a public health perspective, two things fundamentally matter:
1) not exceeding the capacity of the health care system at any point during the epidemic(because this means more deaths for a given number of infections), and
2) the eventual number of infections in the terminal state
The essence of "flatten the curve", temporary hospitals, and ventilators is #1.
#2 you can modify in a couple ways:
A) Late in the game, modest social distancing measures(with low economic impact) can help you get to R <1 at a somewhat lower infection rate. This might get you down from 60% to 50% of the population infected when the disease dwindles away. This is probably underappreciated, because while you'll still have a large number of infections/deaths with this approach, shaving 10-20% of the death toll of this epidemic is still many, many lives - but this will likely go unrecognized because of how high the death toll is going to end up being.
B) The Home Run: If you're aggressive enough, early enough it's possible to do what Australia/Korea appear to have accomplished and knocked infections down to a very, very low level - at which point a large part of the risk can be managed via testing and contact tracing. The thought process here is that at very low infection rates the options for intervention are targeted and much less economically disruptive.
The problem is, to do scenario B effectively, you need to execute it early enough, and aggressively enough. If you don't do it early enough, and are unwilling to be sufficiently aggressive for a long enough time to drive infections low enough that testing/contact tracing/isolation become feasible, you're basically back to the herd immunity endgame.
The reality is, we've most likely missed our window of opportunity to pull off scenario B in the USA(an earlier stoppage of European travel might have changed this story, but we'll never know...). You can't "kind of" do this approach, or do a "toned down" version of it - if you do, the lockdown just runs longer and may not even be sufficiently effective - but that's where we're functionally operating in the USA right now.