The Occupational Safety and Health Administration on Thursday issued a federal rule mandating Covid-19 vaccinations or at least weekly testing for workers at U.S. companies with 100 or more employees.
About 80% of U.S. adults have received at least one dose of the coronavirus vaccines so far.
The new guidance will cover 84 million workers, who will be required to be fully vaccinated or undergo weekly testing.
Businesses face fines of $13,653 for each minor violation of rules meant to boost take-up of jab and as much as $136,532 if the violation is deemed “wilful”.
Companies must ensure that their workers are either fully vaccinated against Covid-19 by Jan. 4 or that they test negative for Covid-19 at least once a week.
Under the OSHA rule, employers must grant paid time off for workers who choose to get vaccinated and provide sick leave for workers to recover from any side effects.
Unvaccinated workers must also wear face coverings while on the job.
President Joe Biden had said in September he would introduce the Covid-19 vaccine mandate as coronavirus infection rates climbed and vaccination rates slowed.
The Biden administration has also said it would help protect workers from Covid, although Republican governors have fiercely opposed it, threatening to sue the administration.
Biden had previously imposed vaccine requirements on federal workers and companies that receive federal contracts.
Separately, a Centers for Medicare and Medicaid Services vaccination requirement covering health-care workers at its 76,000 participating hospitals and other facilities was also introduced Thursday. Enforcement for it too starts Jan. 4.
All 17 million workers at health care facilities receiving either Medicare or Medicaid funding must be vaccinated by Jan. 4.