Get an annual flu shot or get fired.

That policy has become fairly standard in recent years at hospitals and medical facilities across the country. The need to protect patients from influenza overrides employees' personal preferences, health officials say.

But what about someone who isn't in contact with patients, and isn't even technically an employee?

Leonore Tiefer, for example. She got sacked anyway by New York University School of Medicine.

In February, she got a letter from the department chair terminating her appointment because she had flouted the requirement that all "employees, faculty, physicians, contracted staff, volunteers, and students" get the flu vaccine by December. The chair was unconvinced by her letter pointing out that she rarely goes to the NYU Langone Medical Center and has no patient contact.

Tiefer said she supports compulsory immunization programs — for vaccines that are effective. The flu vaccine, she believes, is a different story.

Proponents "make it sound like common sense," she said. "They've convinced themselves that [health worker] flu vaccination protects patients. But the evidence is lacking."

The evidence is conflicting, countered Neil Fishman, an infectious-diseases expert and associate chief medical officer at the University of Pennsylvania Health System. Some studies, especially in nursing homes, show worker flu vaccination reduces patients' flu-related illness and death. Some studies don't.

"There is evidence to support both sides of the argument," Fishman said.

The tension between patient safety and worker autonomy has been apparent since mandatory vaccination policies became common, fueled by the 2009 H1N1 "swine flu" pandemic. Workers can get exemptions for religious or medical reasons such as allergies — but not simply because they don't want the vaccine. Some nurses unions have sued over the mandates. For the most part, though, the law gives employers discretion to hire and fire at will.

Many vaccination policies have been expanded recently to cover non-employees who may have direct patient contact. Penn's directive, for example, requires building contractors, regional organ-transplant workers, and even certain journalists to have flu shots, Fishman said.

Children's Hospital of Philadelphia was among the first to mandate employee vaccination, adopting a policy in 2009 after several infant deaths were linked to health-care workers' flu infections. Bioethicist Art Caplan, who was then at Penn, helped develop the mandate.

Now director of medical ethics at NYU Langone Medical Center, Caplan made a video  that was emailed to people in that health system last fall — including Tiefer — explaining why getting a flu shot is a "moral imperative" for health-care workers.  Caplan asserted they have a duty to "do no harm," protect the vulnerable, and serve as a role model.

"The videos were full of exhortations and guilt-tripping — not full of data or scientific evidence," Tiefer said.

In an interview, Caplan acknowledged that the flu vaccine's effectiveness varies from year to year because the formulation is based on viral strains that are expected to circulate. This year's shot is 43 percent effective against the influenza A variety that has dominated the season, which is now on the wane, according to the government.

The effectiveness "is uneven, there's no denying that," Caplan said. "But it's going to help, and it won't hurt. We're talking about getting a shot, not amputating a limb."

The longer vaccine mandates such as NYU's are in force, the more studies should be able to document the protective effects, Caplan said.

Asked for comment, NYU medical center epidemiologist Michael S. Phillips emailed: "Influenza is more than just a cold. It is a highly contagious disease that causes serious illness — and in some cases death. ... If an employee continues to refuse a shot, he or she can be subject to disciplinary action, including an unpaid leave of absence."

Tiefer, who has written and been quoted widely about the medicalization of sexuality, said she's standing firm, despite losing her NYU privileges.

"I'm doing this because it's offended me, this whole process, and I don't think I should be silent about it," she said.