And when the full focus of society is on getting that cure ? When it is the daily number one priority and target ?
If you lock a part of society away then they will be conveniently forgotten and the focus and urgency on finding the cure will be lost.
Until the virus R-value goes low enough.
If it creeps above another threshold then Lockdown 2 for all.
We need to be all in it together to keep minds focused on a cure.