Footnotes

• Twitter @damian_roland, @mdlyttle

• Collaborators Meriel Tolhurst-Cleaver, Alder Hey Children's Hospital NHS Foundation Trust, Liverpool, England; Stuart Hartshorn, Birmingham Children's Hospital, Birmingham, England; Jessica Watson, Bolton NHS Foundation Trust, Bolton, England; Roisin Begley, Bristol Royal Hospital for Children, Bristol, England; Sakura Hingley, Manali Dutta and Gemma Ramsden, Chelsea and Westminster NHS Foundation Trust, London, England; Eleanor Ryan, Children's Health Ireland at Crumlin, Dublin, Ireland; Sheena Durnin and Stanley Koe, Children's Health Ireland at Tallaght, Dublin, Ireland; Steve Brearey, Countess of Chester NHS Foundation Trust, Chester, England; Darren Ranasinghe, Croydon University Hospital, Croydon, England; Mudiyur Gopi, East Cheshire NHS Trust, England, Macclesfield, England; Patrick Aldridge and Vicky Owens, Frimley Park Hospital, London, England; Simon Richardson, Hull Royal Infirmary, Hull, England; David Hartin, Ipswich Hospital, Ipswich, England; Jiske Steensma and Sahana Rao, John Radcliffe Hospital, Oxford, England; Damian Roland, Leicester Royal Infirmary, Leicester, England; Jo Tillett and Simon Dowson, Leighton Hospital, Crewe, England; Adebayo Da Costa and Alfred Sime, Medway Hospital NHS Foundation Trust, Gillingham, England; Claire Kirby, Newham University Hospital, Newham, England; Adam Lawton, North Middlesex Hospital, London, England; Ruth Wear and Christopher Gough, Nottingham University Hospitals NHS Trust, Nottingham, England; Sharryn Gardner and Craig Rimmer, Ormskirk District General Hospital, Ormskirk, England; Heather Deall, Poole Hospital, Poole, England; Sharon Hall, Queen Elizabeth Hospital, Woolwich, London, England; Catriona Middleton, Royal Aberdeen Children's Hospital, Aberdeen, Scotland; Emily Walton and Friyana Dastur Mackenzie, Royal Alexandra Children's Hospital, Brighton, England; Manish Thakker, Royal Berkshire NHS Foundation Trust, Reading, England; Gisela Robinson and Graham Johnson, Royal Derby Hospital, Derby, England; Steve Foster, Royal Hospital for Children, Glasgow, Glasgow, Scotland; Jen Browning and Lynsey Rooney, Royal Hospital for Children & Young People, Edinburgh, Edinburgh, Scotland; Lorna Bagshaw, Royal Wolverhampton NHS Trust, Wolverhampton, England; Seb Gray, Salisbury NHS Foundation Trust, Salisbury, England; Sally Gibbs, Sheffield Children's NHS Foundation Trust, Sheffield, England; Niall Mullen, South Tyneside and Sunderland NHS Foundation Trust, Sunderland, England; Jane Bayreuther, Southampton Children's Hospital, Southampton, England; Heather Jarman, St George's Hospital, London, London, England; Clare O'Leary, St Helens & Knowsley NHS Trust, Rainhill, England; Raine Astin-Chamberlain, The Royal London, London, England; Lawrence Armstrong and Joanne Mulligan, University Hospital Crosshouse, Kilmarnock, Scotland; Sophie Keers, University Hospital Lewisham, London, England; Richard Burridge, Watford General Hospital (West Herts NHS Trust), Watford, England; Sarah Wilson, Wexham Park Hospital, Slough, England; Amutha Anpananthar, Whipps Cross Hospital, London, England; David Lacy, Wirral University NHSFT, Birkenhead, England.

• Contributors TW, IS, OS: conceptualisation, methodology, writing—original draft preparation, writing—review and editing. MDL: conceptualisation, methodology, project administration, software, writing—original draft preparation, writing—review and editing. SC, DR: conceptualisation, methodology, project administration, writing—original draft preparation, writing—review and editing. AM-H: conceptualisation, methodology, writing—review and editing. PH: methodology, writing—review and editing. RM: methodology, data management.

• Funding This study received financial and administrative support from the Respiratory Syncytial Virus Consortium in Europe (RESCEU) and Paediatric Emergency Research in the UK and Ireland (PERUKI). RESCEU has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement number 116019. This Joint Undertaking receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA. The results reported herein reflect only the authors’ view and not of the European Commission. As such, the EC is not responsible for any use that may be made of the information contained in this publication.

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.