Delta Air Lines will impose a monthly $200 surcharge on unvaccinated employees and require them to get weekly COVID tests, CEO Ed Bastian announced in a memo Wednesday.

Why it matters: The move makes Delta the first major U.S. company to impose a monetary penalty on workers who choose to remain unvaccinated, according to Bloomberg.

Driving the news: While 75% of Delta employees are vaccinated, the move is intended to increase vaccination amid heightened concern over the "very aggressive" Delta variant, Bastian said in the memo.

Details: Beginning Sept. 12, unvaccinated employees will be required to take weekly COVID-19 tests so long as case rates remain high.

• Starting Sept. 30, "COVID pay protection will only be provided to fully vaccinated individuals who are experiencing a breakthrough infection," Bastian added.
• Starting Nov. 1, unvaccinated employees enrolled in Delta's health care plan will receive $200 monthly surcharges to offset the "financial risk" that remaining unvaccinated creates for the company due to the high costs of hospital COVID-19 care.
• Delta Air Lines is also imposing an indoor mask mandate for unvaccinated employees effective immediately.

What they're saying: "While we are grateful for the progress we’ve made, the most recent virus variants make it clear that more work remains ahead," Bastian said.

• "I know some of you may be taking a wait-and-see approach or waiting for full FDA approval. With this week’s announcement that the FDA has granted full approval for the Pfizer vaccine, the time for you to get vaccinated is now."
• "Protecting yourself, your colleagues, your loved ones and your community is fundamental to the shared values that have driven our success for nearly a century."

The big picture: The new measures stopped short of a full vaccine mandate like the one imposed by United Airlines earlier this month.