(Bloomberg) -- The Washington Post will require employees to prove they are vaccinated, joining the ranks of companies that are mandating workers get inoculated against Covid-19 as caseloads rise.

The newspaper, owned by Amazon.com Inc. founder Jeff Bezos, will require employees to show proof of full Covid-19 vaccination “as a condition of employment” when they return to the office in September, Publisher Fred Ryan said in a memo to staff.

The Post will exempt employees with documented medical conditions and religious concerns, he said.

“Even though the overwhelming majority of Post employees have already provided proof of vaccination, I do not take this decision lightly,” Ryan said. “However, in considering the serious health issues and genuine safety concerns of so many Post employees, I believe the plan is the right one.”

Post employees will be expected to be in the office at least three days a week starting Sept. 13, he said. “I urge you to move quickly to arrange for vaccination,” Ryan said.

On Monday, California and New York City announced they would require government employees to get vaccinated or face weekly coronavirus testing, while the U.S. Department of Veterans Affairs said its frontline health-care employees must get the vaccine or possibly be fired.

While media companies have encouraged employees to get the vaccine, they typically don’t require it. Several have begun telling employees to be in the office at least three days a week, starting in September.

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