As workers in industries from healthcare to law enforcement face potential termination ahead of deadlines for individual organizations’ vaccine mandates, questions have arisen about how the Biden administration will enforce its nationwide vaccine mandate on workplaces across the country.

The Occupational Health and Safety Administration is still working on a draft rule requiring all companies with more than 100 employees to mandate vaccines or weekly COVID-19 tests as conditions of employment — more than a month after President Joe Biden announced the rule was coming.