[1] Juliane Marie Centre,The Department of Paediatrics and Adolescent Medicine
[2] Rigshospitalet,Faculty of Health and Medical Sciences
[3] Copenhagen University Hospital,The Department of Paediatrics and Adolescent Medicine
[4] University of Copenhagen,Department of Virus and Microbiological Special diagnostics
[5] Hans Christian Andersen Children’s Hospital,Section of Biostatistics, Department of Public Health
[6] Odense University Hospital,The Department of Paediatrics
[7] National Influenza Center,undefined
[8] Statens Serum Institut,undefined
[9] University of Copenhagen,undefined
[10] Naestved Hospital,undefined