Around 50 employees of a Minnesota healthcare provider have been fired for noncompliance with the organization’s mandatory influenza vaccination policy for workers, according to local reports.

The policy landed Essentia Health, which operates long-term care facilities, hospitals and clinics, in hot water with two unions. One of those unions sued the provider and sought an injunction to block the organization from firing workers who didn’t get the shot. That motion was unsuccessful.

While many workers recently complied with the policy, others refused and failed to meet Essentia’s religious or medical exemption requirements, Rajesh Prabhu, M.D., the provider’s patient quality and safety officer, told the Minneapolis Star Tribune on Tuesday.

“We are working in a different environment,” Prabhu said, citing the fact that ill patients or residents are often at greater risk if they contact the flu. “We’re taking care of patients. We have a different sort of ethical obligation.”

The Minnesota Nursing Association said it plans to file grievances for any nurse who was fired over the policy. The association and the American Federation of State County and Municipal Employees also have filed complaints about the policy with the National Labor Relations Board, the Tribune reported.

Essentia employs more than 12,000 workers in Minnesota, Wisconsin, North Dakota and Idaho. Ninety-nine percent of workers have received the vaccine, Prabhu said.