Patients can refuse a flu shot. Should doctors and nurses have that right, too? That is the thorny question surfacing as U.S. hospitals increasingly crack down on employees who won't get flu shots, with some workers losing their jobs over their refusal. "Where does it say that I am no longer a patient if I'm a nurse," wondered Carrie Calhoun, a longtime critical care nurse in suburban Chicago who was fired last month after she refused a flu shot.