A dozen states have laws requiring that health care workers, with some exceptions, be vaccinated each year for influenza. Minnesota appears in no hurry to join them.

While some research has emerged to suggest that immunizing health care workers protects patients at hospitals and residents at long-term care facilities, the evidence isn’t strong enough to take the somewhat drastic step of a mandate, said Kris Ehresmann, who directs immunization programs for the Minnesota Department of Health.

“If we’re going to mandate something,” she said, “we want to have all of the data on our side, because it’s not something we take lightly.”

A 2013 study highlighted by the U.S. Centers for Disease Control and Prevention reports only moderate evidence that immunizing health care workers reduces the chance of their patients dying from influenza, and only low-grade evidence that this prevents patients from needing additional hospitalizations. The CDC nonetheless recommends vaccinations for health care workers.

Instead of a mandate, Minnesota’s Health Department uses a blue ribbon incentive program to motivate hospitals and long-term care facilities to offer vaccinations and to get 70 percent or more of their employees immunized before each flu season.

Last year, 149 hospitals or nursing homes participated in the state FluSafe program, and 67 had worker vaccination rates of 90 percent or higher.

But the results aren’t always pretty. A labor union sued earlier this fall when Duluth-based Essentia Health tried to achieve a 90 percent vaccination rate by requiring that workers be immunized.

Ehresmann said that both sides should work together on a solution. “They’re thinking of it in terms of an employee-employer relationship,’’ she said. “That is getting in the way of them remembering that their job is to protect the patient, first and foremost.”

Eighteen states have regulations governing the immunization of hospital workers. Some require only that hospitals offer flu shots to workers, or that unvaccinated workers wear masks around patients. But 12 require vaccination.

Ehresmann said there was discussion about a mandate in Minnesota several years ago, but it didn’t result in legislation.