US mandates Covid vaccines or tests for workers at big companies by January 4

A syringe is prepared with the Pfizer Covid-19 vaccine at a clinic at the Reading Area Community College in Reading, Pennsylvania (Matt Rourke/AP)

Tens of millions of Americans who work at companies with 100 or more employees will need to be vaccinated against Covid-19 by January 4 or get tested for the virus weekly under government rules that took effect on Thursday.

The Occupational Safety and Health Administration (OSHA) said companies that fail to comply could face penalties of nearly 14,000 dollars (£10,300) per violation.