Until a vaccine is created, produced and issued to the relevant percentage of the population, herd immunity is really the only protection as a long term lockdown is unsustainable. Where I live, its been 3 weeks of a 'light' lockdown and already companies are stating that they cannot continue indefinitely and a staggered re-open needs to happen after Easter with the elderly and vulnerable remaining isolated.
There's also the mental illness, wellbeing and stress to consider with a longterm lockdown, especially going into the summer season.
The US and UK 'loan system' for private companies just simply won't work for longer than a few weeks. The majority of blue collar service and production industries work on such slim profit margins nowadays that taking a loan will screw them as they won't be able to service the debt once things are up and running again.. What restaurant, for example, makes enough of a profit to pay off another loan..
People will die, its horrific and the result of this virus not being contained in the early stages, but many more will suffer and die of these lock downs are continued into the summer.
It's a precarious and dangerous time.