The old and the sick (I assume you mean the sick with the chronic conditions which have been associated with an increased fatality rate, not the sick with Covid itself, but it would probably work too) are not in daycares and schools.

Daycares and schools are for kids, not for elders. Even as workers, their high unionization rate minimizes the number of elders working there, through retirement. And, unlike hospitals and even prisons, external people aren't supposed to be visiting.

Obviously, adults with infectious diseases have always been prevented from having access to these places because of the safety of children.

So I still think it would be a good idea to have a mass pox party through daycares and schools.