By Suzanne Monaghan

PHILADELPHIA (CBS) — The Hospital and Health System Association of Pennsylvania along with the Pennsylvania Department of Health have a campaign underway encouraging health care workers to get their flu shots.

So far that campaign has been working.

“At least more than half the hospitals in the region have achieved a 90% or more of their health care personnel receiving flu shots,” says Curt Schroder with the Delaware Valley Health Care Council.

Schroder says some health systems are having vaccination clinics and others have made the flu shot mandatory for workers.

“Hospitals have a very strong interest in making sure two things,” he says. “One, that their caregivers are healthy enough to come into work to give care to patients, and two, that while they are there they aren’t spreading flu to vulnerable hospital patients.”

Many hospitals are also restricting visitors in an effort to reduce the spread of the flu.