President Joe Biden has announced that companies with 100 or more employees must have every worker fully vaccinated against COVID-19 by January 4, 2022. Employees who are not vaccinated must provide a negative COVID test at least once a week.

After being first revealed back in September, the new vaccination rules will affect more than 100 million workers in America.

Under the new mandate, issued by the Occupational Safety and Health Administration, workers must get paid time off when they leave to get vaccinated, and the company must give sick leave for workers who need to recover from any side effects from the vaccine. For employees who choose to not get vaccinated, companies are not required to pay for or provide their COVID tests, a rule that seems to favor workers getting vaccinated. People who are not vaccinated must also wear face masks while working at their companies.

Under a different rule, issued by the Centers for Medicare and Medicaid Service, health care workers must be vaccinated by the January 4 deadline and will not have the option for weekly COVID testing. Around 17 million health care workers, both clinical and non-clinical at some 76,000 companies that receive federal funding by Medicare or Medicaid, will be affected by the decision. Federal contractors will also be required to be vaccinated by January 4, separate from federal employees who must do so by November 22.

The decision comes just two days after the CDC approved the Pfizer vaccine for children ages 5-11, which would affect around 28 million kids who were previously unable to be vaccinated.