Are those hypothetical or real cases? I can’t imagine real ones, because someone who doesn’t wear a mask as staff in a hospital would not be staying there long. Or are masks not mandatory in hospitals where you live? We have been wearing surgical masks at work for a long time now ( I am guessing its a year now). When the second wave started and we had a local hot spot, we were also wearing visors, despite not even having active cases in the hospital.
For the second one- so far, vaccinations are not mandatory. So, theoretically, someone could work at a vaccination clinic and not being vaccinated. However, considering that that person could be infected without symptoms, I think that he/ she should have regular tests done.
Germany has started to offer every person two free covid quick tests per week. Schools are doing tests twice a week, which resulted in the discovery that the highest incidence of covid cases was in 6-9 year olds who didn’t have any symptoms.
In my mother’s nursing home, they are testing every employee at least twice a week. So, while one can’t force people to be vaccinated, testing can be a mandatory requirement for the job.