“That case is a real problem for vaccine mandate skeptics,” said Nicholas Bagley, a University of Michigan law professor who specializes in administrative and health care law. For employers, almost anything goes for vaccine mandates for workers More and more Some companies have instituted straight-up requirements for vaccines for their employees, with those employees refusing to comply being shown the door. Other employers have given workers a choice: get the vaccine, or subject yourself to an onerous set of rules, like weekly tests, mask requirements and social distancing demands. Many public employers, including several federal agencies, are adopting that latter approach.