ANN ARBOR, Mich. (AP) — The University of Michigan Health System says all its employees are being required to get flu vaccines as part of an effort to ensure patient safety.

The Ann Arbor News reports that the policy requires vaccines before Dec. 1 except for those who provide medical or religious documentation.

Employees with exemptions will be required to wear a mask upon entering all health system patient care facilities for the remainder of the flu season.

An email from the health system says the policy “applies to everyone who works at our health system, including regular and temporary staff, faculty, students, trainees, vendors, contract personnel and volunteers, regardless of clinical responsibility or patient contact.”

Previously, the newspaper says only those working in clinical care areas were required to get flu vaccines.