US mandates vaccines or tests for big companies by Jan. 4

FILE - In this Sept. 14, 2021, file photo, a syringe is prepared with the Pfizer COVID-19 vaccine at a clinic at the Reading Area Community College in Reading, Pa. Millions of U.S. workers now have a Jan. 4 deadline to get a COVID vaccine. The federal government on Thursday, Nov. 4, 2021 announced new vaccine requirements for workers at companies with more than 100 employees as well as workers at health care facilities that treat Medicare and Medicaid patients.. (AP Photo/Matt Rourke, File)

FILE - In this Oct. 21, 2020, file photo, an Exam Corp Lab employee, right, wears a mask as she talks with a patient lined up for COVID-19 testing in Niles, Ill. Millions of U.S. workers now have a Jan. 4 deadline to get a COVID vaccine. The federal government on Thursday, Nov. 4, 2021 announced new vaccine requirements for workers at companies with more than 100 employees as well as workers at health care facilities that treat Medicare and Medicaid patients. (AP Photo/Nam Y. Huh, File)

In this Saturday, Oct. 23, 2021, photograph, a sign notifies customers that COVID-19 vaccinations are available at a pharmacy in a grocery store in Monument, Colo. Millions of U.S. workers now have a Jan. 4 deadline to get a COVID vaccine. The federal government on Thursday, Nov. 4, 2021 announced new vaccine requirements for workers at companies with more than 100 employees as well as workers at health care facilities that treat Medicare and Medicaid patients. (AP Photo/David Zalubowski)

Tens of millions of Americans who work at companies with 100 or more employees will need to be fully vaccinated against COVID-19 by Jan. 4 or get tested for the virus weekly under government rules issued Thursday.