United Airlines has announced it will require all new external hires to prove they have been fully vaccinated against COVID-19. The move comes about a month after fellow American legacy carrier Delta Air Lines began requiring vaccinations for new hires.

All external candidates who receive job offers after June 15 must confirm they have been fully vaccinated by their start date. United says that new employees will be required to upload their COVID vaccine card in My Info no later than 7 days post-hire date.

“As we welcome new employees to the company, it’s important we instil in them United’s strong commitment to safety,” the airline said in its note to staff.

This announcement shouldn’t come as a surprise. In January, company CEO Scott Kirby announced he wanted vaccines to be mandatory for all employees.

“The worst thing that I believe I will ever do in my career is the letters that I have written to the surviving family members of co-workers that we have lost to the coronavirus,” Kirby said at the time in an employee town hall.

“And so, for me, because I have confidence in the safety of the vaccine – and I recognize it’s controversial – I think the right thing to do is for United Airlines, and for other companies, to require the vaccines and to make them mandatory,” Kirby continued.

While vaccines are not yet required for current employees, United has joined Delta and American Airlines to offer extra time off or bonuses to employees who are vaccinated. United did reach an agreement last month with its pilots’ union to keep the shot voluntary with incentives like bonuses and extra time off in place.

In addition, United says that it will be restricting “positive-space travel” for U.S.-based staff to and from locations outside of the U.S. and its territories if they have not provided proof of at least one vaccine dose. This likely means that any employee who wants to fly abroad for work will need to be vaccinated.

Across the global aviation industry, there has been a massive push to get employees vaccinated. Many airlines, like Qatar Airways, are using fully vaccinated flight crews as marketing points to help customers feel safer on flights. Alliance Airlines and airBaltic will both require vaccines for their employees, and all El Al’s customer-facing staff have been vaccinated by February.

United hasn’t been focused simply on vaccinating employees. In an effort to encourage passengers to get vaccinated, the airline created sweepstakes offering fully-vaccinated passengers a chance to win free flights for a year or a roundtrip flight to any destination in the United States.

Since virtually the start of the coronavirus pandemic, airlines have maintained that no recovery is possible without mass vaccination efforts. Indeed, with vaccinations on the rise and coronavirus cases dropping rapidly in the United States, airlines – United included – have seen massive upticks in bookings that have led them to boost flight schedules to near-pre-pandemic levels. United itself has added a number of international leisure routes for the second half of 2021 in the past few months.

It would be hard to manage this policy where the existing staff which are about 60.000 people are not obliaged to be vaccinated and the new joiner have to be vaccinated, I am not even sure what benefits would this add.