Mary is a professor in the Department of Emergency Medicine at University of California, San Francisco, where she is the Director of the Emergency Medical Services (EMS) and Disaster Medicine Section and fellowship program. She works clinically at San Francisco General Hospital and Trauma Center, where she also serves as the Chief of the Medical Staff. Dr. Mercer is a national leader in prehospital emergency care with clinical and research expertise in the domains of healthcare operations, performance improvement, and public health. She has worked closely with local and statewide disaster preparedness and response efforts, including serving as the primary architect of San Francisco’s successful COVID-19 vaccine campaign.