1 Epidemiology Department, Epiconcept, Paris, 75011, France.
2 Department of Communicable Diseases, National Centre of Epidemiology, Institute of Health Carlos III, Madrid, 28029, Spain.
3 Centre for Infectious Diseases Control, National Institute for Public Health and the Environment, Bilthoven, 3721, The Netherlands.
4 National Laboratory for Health Security, Epidemiology and Surveillance Centre, Semmelweis University, Budapest, 6720, Hungary.
5 Epidemiology Department, National Health Institute Doutor Ricardo Jorge, Lisbon, 1649-016, Portugal.
6 Department of Microbiology, The Public Health Agency of Sweden, Stockholm, 103 33, Sweden.
7 Division for Epidemiology of Communicable Diseases, Croatian Institute of Public Health, Zagreb, 10000, Croatia.
8 National Influenza Centre, Cantacuzino National Military-Medical Institute for Research and Development, Bucharest, 050096, Romania.
9 Subdirecció General d'Epidemiologia i Vigilància de la Salut, Direcció General de Salut Pública, Generalitat Valenciana, València, 46020, Spain.
10 Department for Infectious Disease Epidemiology, Respiratory Infections Unit, Robert Koch Institute, Berlin, 13353, Germany.
11 Réseau Sentinelles, Sorbonne Université, INSERM, Institut Pierre Louis d'épidémiologie et de Santé Publique (IPLESP), 75012, Paris, France.
12 Health Service Executive-Health Protection Surveillance Centre, Dublin, D01 A4A3, Ireland.
13 Instituto de Salud Pública de Navarra-IdiSNA, Pamplona, 31008, Spain.
14 CIBER Epidemiología y Salud Pública, Madrid, 28029, Spain.
15 Nivel (Netherlands Institute for Health Services Research), Utrecht, 3513, The Netherlands.
16 Reference Laboratory for Influenza and Other Respiratory Virus, National Institute of Health Doutor Ricardo Jorge, Lisbon, 1649-016, Portugal.
17 Department of Microbiology, Public Health Agency of Sweden, Stockholm, 103 33, Sweden.
18 Subdirección de Epidemiología, Dirección General de Salud Pública, Servicio Extremeño de Salud, Mérida, 06800, Spain.
19 Department of Infectious Diseases, Unit 17 Influenza and Other Respiratory Viruses, National Reference Centre for Influenza, Robert Koch Institute, Berlin, 13353, Germany.
20 Centre National de Référence Virus des Infections Respiratoires (CNR VIR), M3P, Institut Pasteur, Université Paris Cité, Paris, 75015, France.
21 M3P, Institut Pasteur, Université Paris-Saclay, Université de Versailles St. Quentin, Université Paris Cité, UMR 1173 (2I), INSERM, Assistance Publique des Hôpitaux de Paris, Paris, 75015, France.
22 Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, 3721, The Netherlands.
23 Vaccine Preventable Disease and Immunisation, European Centre for Disease Prevention and Control, Stockholm, 171 83, Sweden.