Contributed By Scott Lipscomb

CNN has fired three employees who violated company policy by coming to work unvaccinated against the COVID-19 virus.

CNN chief Jeff Zucker told staff members of the firing in a memo sent Thursday that reminded them that vaccines were mandatory if they report to the office or out in the field where they come into contact with other employees.

“Let me be clear — we have a zero tolerance policy on this,” wrote Zucker, chairman of news and sports for WarnerMedia.

Most of CNN’s offices are already open on a voluntary basis, and Zucker said more than a third of news staff members have returned. Proof of vaccination has been left to the honor system, he said, but that may change in coming weeks USA Today Reported.

CNN is requiring masks in indoor spaces as another precaution even with the vaccination . Even in offices where mask-wearing is not mandated, people should do what feels comfortable to them “without any fear of retaliation or judgment from co-workers,” he said.

The CNN memo also said a planned Sept. 7 company-wide return to the office will be delayed until at least early to mid-October.