This sounds like an opportune time to introduce something I suggested (somewhat tongue-in-cheek, TBF) when youth unemployment was at its highest, that we should start the State Pension for everyone from the age of 60, and make it illegal to employ someone over that age (though they could be self employed within certain restrictions).
The impression I get about the virus is that those most at risk of dying are those over the age of, say, 50 and those with underlying health problems. Anyone not in those groups who gets the virus is pretty much certain to recover. So within the employment restrictions I've described above, everyone under, say, 45 with no underlying health problems can return to work provided their employer follows the distancing guidelines etc; 45-60 year-olds and those with health problems get furloughed until there's a vaccine; those over 60, welcome to retirement - let's hope it's a long one.
The big problem with people going back to work, is not necessarily the worker themselves, who'll likely recover if they catch the virus, but to anyone "at risk" they may pass the virus on to. And I can't see any real alternative to those "at risk" having to permanently hunker down, at least until there's a vaccine.