"The two largest unions at the airline — the Association of Flight Attendants and the Air Line Pilots Association — both issued statements to their members Friday suggesting the unions will accept the mandate. The flight attendants’ union said 80% of its members are vaccinated, while the pilots’ union said more than 90% for its members."
https://www.cnn.com/2021/08/06/business/united-airlines-vaccine-mandate/index.html