Imperial College London - Section of Virology, Imperial College London - Section of Adult Infectious Disease, Imperial College London - Section of Virology, Imperial College London - Section of Virology, Imperial College London - Section of Virology, Imperial College London - Section of Virology, University of Nottingham - Health Protection and Influenza Research Group, hVIVO Services Ltd, hVIVO Services Ltd, hVIVO Services Ltd, University of Leicester - Department of Respiratory Sciences, Imperial College London - MRC Centre for Global Infectious Disease Analysis, Imperial College London - Section of Adult Infectious Disease and Imperial College London - Section of Virology

University of Nottingham - School of Medicine, University of Nottingham - Health Protection and Influenza Research Group, University of Nottingham - Health Protection and Influenza Research Group, University of Nottingham - Health Protection and Influenza Research Group, University of Maryland - School of Public Health, University of Maryland - School of Public Health, University of Maryland - School of Public Health, hVIVO, hVIVO, hVIVO, hVIVO, University of Leeds - School of Civil Engineering, Centers for Disease Control and Prevention - Division of Influenza, Centers for Disease Control and Prevention - Division of Influenza, Centers for Disease Control and Prevention - Division of Influenza, Imperial College London - MRC Centre for Outbreak Analysis and Modelling, Wake Forest University - School of Medicine, University of Calgary - Cumming School of Medicine, University of Maryland - School of Public Health and Independent