By Emily Rella Many major companies and employers are doubling down on vaccination requirements for their employees and staff, some going as far as to make it a requirement without the ability to opt out and wear a mask. Last week, United Airlines became the first major U.S. airline to require that all of its employees be vaccinated or risk termination from the company, settling a deadline of October 27. Frontier Airlines also announced their own mandatory employee vaccination policy, which will go into effect on Oct. 1. “Safety is of the utmost importance at Frontier, and we need to take every step possible for us to keep our teams safe, protect the operation and protect our passengers,” Frontier Airlines CEO Barry Biffle said in a statement released last week. But American Airlines made waves by traveling in a different direction. CEO Doug Parker spoke on New York Times contributor Kara Swisher’s Sway podcast …