Through OSHA (Occupational Safety and Health Administration). I.E. viewing unvaxxed employees as making the workplace unsafe. Businesses that don't comply will be fined.
Patriots should have fought hard against OSHA in the first place, because the whole concept violates the Constitution directly.
"A senior administration official estimated that this new OSHA requirement will cover about 80 million workers and businesses that do not comply with the agency’s rule can face substantial fees"
I used to work in occupational health and safety in the private sector and I can tell you that OSHA doesn't have the resources to manage what it currently has let alone trying to take this on.