1. These authors contributed equally as first authors
2. World Health Organization (WHO) Regional Office for Europe, Copenhagen, Denmark
3. European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
4. Medical University of Vienna, Centre for Virology, Vienna, Austria
5. Medical and Public Health Services, Nicosia, Cyprus
6. Centre for Health Security and Communicable Disease Control, Directorate of Health, Reykjavik, Iceland
7. United Kingdom Health Security Agency, London, United Kingdom
8. Center for Disease Prevention and Control of Latvia, Department of Infectious Diseases Risk Analysis and Prevention, Riga, Latvia
9. Ministry of Health, Rome, Italy
10. Santé publique France, the French National Public Health Agency, Saint-Maurice, France
11. National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria
12. Division of Epidemiology, Ministry of Health, Jerusalem, Israel
13. Department of Epidemiology and Public Health, Sciensano, Brussels, Belgium
14. National Centre of Epidemiology, CIBER in Infectious Diseases (CIBERINFEC), Carlos III Health Institute, Madrid, Spain
15. National Institute of Public Health, Centre for Epidemiology and Microbiology, Department of Infectious Disease Epidemiology, Prague, Czechia
16. Norwegian Institute of Public Health (NIPH), Oslo, Norway
17. NIJZ (NIPH), Centre for Communicable Diseases, Ljubljana, Slovenia
18. Finnish Institute for Health and Welfare, Helsinki, Finland
19. Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark
20. HSE Public Health: National Health Protection Office, Dublin, Ireland
21. Department for Infectious Disease Epidemiology, Robert Koch Institute, Berlin, Germany
22. National Institute of Public Health, Bucharest, Romania
23. Directorate of Epidemiological Surveillance and Intervention for Communicable Diseases, National Public Health Organization, Marousi, Greece
24. Department of Infectious Diseases, Rigshospitalet University Hospital, Copenhagen, Denmark
25. Andrija Stampar Teaching Institute of Public Health, Zagreb, Croatia
26. Swiss Federal Office of Public Health, Bern, Switzerland
27. Santé publique France, the French National Public Health Agency, Saint-Denis, France
28. Croatian Institute of Public Health, Division for Epidemiology of Communicable Diseases, Zagreb, Croatia
29. School of Health Sciences, Ashkelon Academic College, Ashkelon, Israel
30. HSE Health Protection Surveillance Centre, Dublin, Ireland
31. Austrian Agency for Health and Food Safety, Vienna, Austria
32. Department of Epidemiology and Biostatistics, Third Faculty of Medicine, Charles University, Prague, Czechia
33. Public Health Agency of Sweden (PHAS), Solna, Sweden
34. National Institute of Public Health NIH - National Research Institute, Warsaw, Poland
35. Coordinating Centre for Health Alerts and Emergencies (CCAES), Directorate General of Public Health, Ministry of Health, Madrid, Spain
36. Public Health Emergency Centre, Directorate-General of Health (DGS), Lisbon, Portugal
37. Directorate of Information and Analysis, Directorate-General of Health, Lisbon, Portugal
38. These authors contributed equally as last authors