Herd immunity is the ONLY viable answer.
Keep the sick and those most likely to suffer the most away from everyone else, period, full stop: the elderly with any possible co-morbidity.
Let everyone else assume regular life.
Some will get sick but few, if any, would die. We all would become immune, and the virus dies off. Then let the oldsters out.
Is there a better way?
Is not that what we did as kids, when our parents wanted us to play with the neighborhood kids with measles, chickenpox and mumps, while oldsters who never had those diseases or vaccines were kept far away?