The pharmacy itself should have policies preventing sick employees from attending work and have generous paid sick leave.
We could reduce disease transmission and thus social cost dramatically if we reduced transmission in medical contexts (e.g. hospitals are one of the main places people GET sick -- from other patients).
It would ultimately save money if there was overstaffing requirements and stringent no sick staff allowed in any medical context.
The problem is that cost reduction is at a societal level while individual firms don't have the incentive to do this. But socialized healthcare systems should be able to solve this easily.
I really wish that the situation could be better but unfortunately the huge cuts made since the financial crisis have made that impossible.
Doctors have the same problem.
They all get it every year anyway because they're constantly coming into contact with sick people so there's less benefit for staying at home.