United Airlines informed its U.S employees Friday they need to be vaccinated against COVID-19 by late October, becoming the first major airline to implement such a mandate.

In a memo to employees, United CEO Scott Kirby and President Brett Hart said while they realize some workers may disagree with their decision, “the facts are crystal clear: everyone is safer when everyone is vaccinated.”

Employees who fail to do so will be fired. The company says it will allow for religious or medical exemptions but will require documentation to prove them.

United has about 67,000 employees in the United States. The airline says about 90 percent of its pilots and 80 percent of its flight attendants are already vaccinated.

The airline joins a growing list of major employers that have implemented vaccine mandates.  Earlier this week, Microsoft announced it was also requiring workers to provide proof of a coronavirus vaccination before entering its U.S. offices.

Tuesday, U.S.-based Tyson Foods, one of the world’s largest meat-producing companies, said it is requiring all its employees to be fully vaccinated.

The federal government said in May it was legal for employers to require their workers to get vaccinated.

Source: Voice of America