Background: Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in older adults that can result in hospitalisations and death. Estimating RSV-associated hospitalisation is critical for planning RSV-related healthcare needs for the ageing population across Europe. Methods: We gathered national RSV-associated hospitalisation estimates from the REspiratory Syncytial virus Consortium in EUrope (RESCEU) for adults in Denmark, England, Finland, Norway, Netherlands, and Scotland from 2006 to 2017. We extrapolated these estimates to 28 EU countries using nearest-neighbour matching, multiple imputations, and two sets of 10 indicators. Results: On average, 158 229 (95%CI: 140 865, 175 592) RSV-associated hospitalisations occur annually among adults in the EU (above 18 years); 92% of these hospitalisations occur in adults over 65 years. Among 75-84 years old, the annual average is estimated at 74 519 (95%CI: 69 923, 79 115) at a rate of 2.24 (95%CI: 2.10, 2.38) per 1000 adults. Among adults aged 85 years and above, the annual average is estimated at 37 904 (95%CI: 32 444, 43 363) at a rate of 2.99 (95%CI: 2.56, 3.42). Conclusion: Our estimates of RSV-associated hospitalisations in older adults are the first analysis integrating available data to provide estimates of the disease burden in this population across the EU. Importantly, for a condition which was considered in the past to be primarily a disease of young children, the average annual hospitalisation estimate in adults was lower but of a similar magnitude to the estimate in young children aged 0-4 years: 158 229 (95%CI: 140 865, 175 592) versus 245 244 (95%CI: 224 688, 265 799).

HC reports grants, personal fees, and nonfinancial support from World Health Organization. Grants and personal fees from Sanofi Pasteur. Grants from Bill and Melinda Gates Foundation. All payments were made via the University of Edinburgh. HC is a shareholder in the Journal of Global Health Ltd. JP declares that Nivel has received unrestricted research grants regarding the epidemiology of RSV from Sanofi Pasteur and IMI in the past 12 months. All other authors report no potential conflicts.

This work is part of RESCEU. RESCEU has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 116019. This Joint Undertaking receives support from the European Union Horizon 2020 research and innovation programme and EFPIA. This publication only reflects the authors view and the JU is not responsible for any use that may be made of the information it contains herein.

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The study used ONLY openly available data that were originally located at: https://academic.oup.com/jid/article/226/Supplement_1/S29/6617433?login=true

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

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I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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All data produced in the present study are available upon reasonable request to the authors and/or the RESCEU Steering Committee