量化疫苗接种对欧盟/欧洲经济区老年人新冠肺炎和流感住院负担影响的多模型分析，2024/25

Multi-model analysis to quantify the impact ofvaccination on COVID-19 and influenza hospitalisation November 2025 Executive summary Influenza vaccine coverage remains below the World Health Organization (WHO)-recommended thresholdfor risk groups in most EU/EEA countries, while COVID-19 vaccine coverage is declining across mostcountries. Despite the role that vaccines play in reducing severe disease, a comprehensive EU/EEA-widequantification and assessment of the impact of influenza and COVID-19 vaccination programmes on To address this, we quantified the expected impact of vaccination programmes using a collaborative modellingapproach through RespiCompass, the European respiratory diseases scenario modelling hub(https://respicompass.ecdc.europa.eu). This hub coordinated the development of multiple mechanistic diseasetransmission models by international modelling teams to simulate scenarios designed to assess vaccination Our analysis suggests a clear reduction in influenza and COVID-19 hospitalisations due to vaccination in theEU/EEA between 5 August 2024 and 1 June 2025. This reduction varies strongly between countries withdifferent vaccine coverage levels. For individuals 65 years old and above, influenza vaccination was projectedto prevent – on average across EU/EEA countries – between 26% and 41% of influenza-relatedhospitalisations over the 2024/25 epidemiological season, depending on assumed country-specific vaccine A large heterogeneity across countries was observed for the impact of vaccination on both diseases,reflecting differences in vaccine coverage. Depending on the modelled scenario, the difference in avertedhospitalisations between the country with highest versus lowest averted burden was between 48 and 70percentage points for influenza, and between 37 and 54 percentage points for COVID-19. This inter-country variation highlights the untapped potential to reduce hospital burden in the EU/EEAthrough established programmes, such as seasonal influenza vaccination, as well as newer interventions likeCOVID-19 vaccination. At a time when a number of EU/EEA countries are assessing routine immunisation Introduction Vaccine coverage for both influenza and COVID-19 varies widely across EU/EEA countries [1-3], influenced byfactors such as national immunisation policies [4,5], public perception, logistical constraints and pandemic fatigue[6-8]. In particular, COVID-19 booster dose coverage has decreased over recent successive campaigns, despitecontinued recommendations for high-risk and priority groups. This declining coverage raises concerns about thepotential resurgence of severe disease burden, particularly among older adults (aged 60 years old and above) andother high-risk groups [9,10]. For COVID-19 vaccination, countries also differ in the extent to which strategies While empirical evaluations such as clinical vaccine effectiveness studies conducted at representative primary andsecondary care sentinel surveillance sites provide valuable real-world evidence, they face important limitations. Thesestudies are not meant to assess the impact of vaccination programmes, but the effectiveness of vaccines in preventingspecific outcomes. Additionally, it is difficult for these studies to achieve sufficient sample sizes or extrapolate resultsacross countries in a region, and results can be influenced by confounding factors such as concurrent public healthmeasures or prior infection levels. Ethical constraints also limit the range of scenarios that can be studied, such as The purpose of this analysis was to estimate the impact of influenza and COVID-19 vaccination on hospitalisationburden among older adults in the EU/EEA using a multi-model approach that combined results from severalindependently developed models to generate aggregated ensemble estimates [21-24]. This assessment provides Methods The modelling effort for this analysis was coordinated through RespiCompass, the European respiratory diseasesscenario modelling hub. RespiCompass is a multi-model scenario hub launched by ECDC in 2024 to assessrespiratory disease burden and intervention impacts in the EU/EEA [25]. Collaborative modelling approaches suchas RespiCompass combine projections from independently developed models to explore a range of plausible Hospitalisation burden is a critical metric to assess the public health impact of vaccination because it is a robustindicator of severe disease and healthcare system strain, as well as economic costs [50-52]. Therefore, this analysisfocused on the question: what is the averted hospitalisation burden of COVID-19 and influenza due to vaccinationamong those 65 years old and above in winter 2024/25? To address this question, a group of international modelling Below, we describe the scenarios and assumptions that guided the work of modelling teams, the supporting dataand modelling outputs, as well as the methods used to analyse the modelling outputs. References to ‘season’ whendiscussing dise