1. Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich , Zurich , Switzerland
2. Institute of Medical Virology, University of Zurich , Zurich , Switzerland
3. Checkpoint Zurich , Zurich , Switzerland
4. Department of Public and Global Health, Epidemiology, Biostatistics and Prevention Institute, University of Zurich , Zurich , Switzerland