1. Institute of Medical Virology, University of Zurich, Zurich, Switzerland
2. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland
3. University Hospital Lausanne, University of Lausanne, Lausanne, Switzerland
4. Division of Infectious Diseases, Regional Hospital of Lugano, Lugano, Switzerland
5. Division of Infectious Diseases, Cantonal Hospital of St. Gallen, St. Gallen, Switzerland
6. Division of Infectious Diseases, University Hospital of Geneva, Geneva, Switzerland
7. Division of Infectious Diseases, University Hospital of Basel, Basel, Switzerland
8. Department of Infectious Diseases, University Hospital of Bern, Bern, Switzerland
9. Laboratory of Virology, Division of Infectious Diseases, Geneva University Hospital, Geneva, Switzerland
10. Division of Immunology and Allergy, University Hospital Lausanne, Lausanne, Switzerland
11. Department of Biomedicine-Petersplatz, University of Basel, Basel, Switzerland