Public health experts urge most Americans to protect their health — and shield those around them — by getting a flu shot every year. That's particularly vital for people like nurses, who care for elderly and ill people. That's why the Cook County Health and Hospitals System requires all of its workers to be vaccinated against the flu. There are patients to protect. But some of the Cook County system's nurses seek a pass. The union that represents most of the system's nurses, the National Nurses Organizing Committee, has appealed to the Illinois Labor Relations Board to stop Cook County health officials from forcing nurses to get a flu shot.