United Airlines says more than 97 per cent of its U.S.-based employees are fully vaccinated against the coronavirus now that there’s less than a week before a deadline to get the shots or get fired.

The Chicago-based airline said Wednesday that the new figure doesn’t include a “small number” of employees who are seeking a medical or religious exemption from vaccination. “Vaccine requirements work,” said United in a memo to employees.

Read: Unvaccinated Air Canada employees facing unpaid leave, termination

Six United employees sued the company this week, claiming the airline is discriminating against employees who get exemptions from the vaccine mandate by placing them on unpaid leave. “United’s actions have left plaintiffs with the impossible choice of either taking the COVID-19 vaccine, at the expense of their religious beliefs and their health, or losing their livelihoods,” say lawyers for the employees in their lawsuit, which was filed in federal district court in Fort Worth, Tex.

Four of the six employees said they sought religious exemptions based on their belief that the vaccines were developed using aborted fetal tissue, one said she’s allergic to eggs and penicillin and another said he has multiple sclerosis and his neurologist recommended against vaccination. All were granted exemptions but were still told by the company they’d be put on unpaid leave, according to the lawsuit.

United Airlines’ spokesperson Leslie Scott said the company was “reviewing this complaint in greater detail, but at this point we think it’s without merit.” The airline said last month that up to 90 per cent of pilots and nearly 80 per cent of flight attendants were vaccinated, but it didn’t give a figure for all U.S. employees at the time.

Read: Transat, WestJet employee vaccination policies taking flight

United said it will start termination proceedings as soon as next Tuesday against employees who are unvaccinated and haven’t received an exemption. The airline is among a small group of companies that announced they would require vaccinations even before Sept. 9, when U.S. President Joe Biden issued an executive order directing employers with more than 100 workers to require vaccinations or weekly testing for the virus.

Last month, United set a deadline of Sept. 27 for its 67,000 U.S.-based employees to get vaccinated or face termination. However, employees who apply unsuccessfully for an exemption could get more time. They’ll have five weeks after their denial to get vaccinated.

United declined to give a precise figure for how many workers have asked for an exemption and how many requests have been granted. Employees who win an exemption will be placed on leave beginning Oct. 2. Some could come back if they wear masks and are tested weekly, although the timing of their return is uncertain.

Read: Delta Air Lines charging unvaccinated employees on company health plan US$200 per month