The San Francisco Department of Health has issued a Health Officer order mandating that all hospitals, skilled nursing, and other long term care facilities in the City and County of San Francisco require their health care workers (HCWs) to receive an annual influenza vaccination or, if they decline, to wear a mask in patient care areas during this flu season. Influenza infection accounts for 36,000 excess deaths in the U.S. each year; 90% of which are people over the age of 65. HCWs are both at risk for influenza and can transmit the virus to their patients. The goal is to increase influenza vaccination rates of HCWs, reduce employee absenteeism during the flu season, and reduce HCW to patient transmission of influenza. The influenza season is defined as December 15 to March 31. Click here for more information and a copy of the Health Officer order .