[SpinyNormal61]

The commonly stated goal of lockdowns is to slow the spread, flatten the (new cases vs time) curve, and thereby try to manage the rate of new cases so hospital resources (ICU beds, respirators, nursing staff) arn't overwhelmed.

Once (whenever that may be) the curve is shown to be flattening and hostpitals are in control, it'd be logical to see some gradual loosening of the restrictions that are currently being ramped up.

I personally doubt that loosening of restrictions, once above conditions are met, will be contingent on a proven and widely available vaccine having been developed (not least because there's no guarantee that one ever will be).

At this point it's anyone's guess how long it'll be in any given country until things appear to be more under control... Even in South Korea, who seem to have done best job in containing this, I've yet to see any estimates of how long it'll take at current rates on infection for the majority of the population to get it and/or get to "herd immunity" point.

In the US all bets are off.. it seems we were (and still are) extraordinarily slow to recognize the severity of this and take appropriate actions (severe lockdowns, widespread testing and resulting case tracking), so a reasonable expectation is that we may be following the case trajectories of the harder hit countries, with similar measures as they have in place coming to the US.