A United Airlines Boeing 777-200ER is towed while an American Airlines Boeing 737 departs from O’Hare International Airport in Chicago, Illinois.

Kamil Krzaczynski | Reuters

Starting this month, following a similar move by Delta Air Lines, United Airlines will require new employees to provide evidence that they have been vaccinated against Covid-19.

The new rule requires outside applicants with job vacancies submitted after June 15 to confirm that they are fully vaccinated by their start date, the Chicago-based airline said.

The move comes as companies grapple with the question of whether to vaccinate their employees or find a way to incentivize vaccination. United, Delta, and American have offered vaccinated employees additional time off or pay. Big employers like Walmart have taken similar measures.

“As we welcome new employees to the company, it is important that we convey United’s strong commitment to safety,” the airline said in a statement to employees previously by Brian Sumers, editor-in-chief of the travel industry site , Skift was tweeted.

The new employees “have to upload their COVID vaccination card to My Info no later than 7 days after the hiring date,” said the airline. The company added that it will evaluate any religious or medical circumstances of candidates who cannot be vaccinated.

United CEO Scott Kirby said in January that he wanted to make Covid vaccines mandatory for employees, but the airline hasn’t taken that step.

Airlines have spent much of the last year downsizing, but airlines like United have announced that they will resume hiring pilots and other positions when travel demand picks up again.