Figure. Worker exclusion and testing in a study of the effectiveness of booster and influenza vaccines against COVID-19 among healthcare workers, Taipei Tzu Chi Hospital, Taipei, Taiwan. Employment, vaccination, and testing data for April 10–June 10, 2022, were provided by the hospital’s Human Resource Office and corroborated by the Occupational Safety and Health Administration Office and the hospital’s Center for Infection Control. Workers in the routine testing group were tested weekly by reverse transcription PCR or rapid antigen test; workers in the symptom-triggered testing group were tested if COVID-19 symptoms developed or after they were exposed to COVID-19 cases. HCW, healthcare worker.