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oai:repisalud.isciii.es:20.500.12105/259402025-12-18T12:59:49Zcom_20.500.12105_2052com_20.500.12105_2051com_20.500.12105_15322col_20.500.12105_19608col_20.500.12105_16968

00925njm 22002777a 4500 dc Nunes, Baltazar author Humphreys, James author Nicolay, Nathalie author Braeye, Toon author Van Evercooren, Izaak author Holm Hansen, Christian author Moustsen-Helms, Ida Rask author Sacco, Chiara author Fabiani, Massimo author Castilla, Jesús author Martínez-Baz, Iván author Meijerink, Hinta author Machado, Ausenda author Soares, Patricia author Ljung, Rickard author Pihlström, Nicklas author Nardone, Anthony author Bacci, Sabrina author Monge Corella, Susana author VEBIS-EHR Working Group author 2024 Background: We aimed to estimate XBB.1.5 vaccine effectiveness (VE) against COVID-19-related hospitalizations and deaths during BA.2.86/JN.1 predominance, among EU/EEA individuals with ≥65-years. Research design and methods: We linked electronic health records to create historical cohorts in Belgium, Denmark, Italy, Navarre (Spain), Norway, Portugal and Sweden. We included individuals aged ≥65-years eligible for the autumnal 2023 COVID-19 vaccine. Follow-up started when ≥80% of country-specific sequenced viruses were BA.2.86/JN.1 (4/dec/23 to 08/jan/24) and ended 25 February 2024. At study site level, we estimated the vaccine confounder-adjusted hazard ratio (aHR) of COVID-19 hospitalizations and deaths between individuals with ≥14 days after vaccination versus unvaccinated in autumn 2023, overall, by time since vaccination and age groups. VE was estimated as (1-pooled aHR)x100 with a random-effects model. Results: XBB.1.5 VE against COVID-19 hospitalizations was 50% (95%CI: 45 to 55) and 41% (95%CI: 35 to 46) in 65-79-year-olds and in ≥80-year-olds, respectively. VE against COVID19-related-death was 58% (95%CI: 42 to 69) and 48% (95%CI: 38 to 57), respectively, in both age groups. VE estimates against each outcome declined in all age groups over time. Conclusion: Monovalent XBB.1.5 vaccine had a moderate protective effect against severe and fatal COVID-19 likely caused by BA.2.86/JN.1 during the 2023/2024 winter, among persons aged ≥65. Nunes B, Humphreys J, Nicolay N, Braeye T, Van Evercooren I, Holm Hansen C, Moustsen-Helms IR, Sacco C, Fabiani M, Castilla J, Martínez-Baz I, Meijerink H, Machado A, Soares P, Ljung R, Pihlström N, Nardone A, Bacci S, Monge S; VEBIS-EHR working group. Monovalent XBB.1.5 COVID-19 vaccine effectiveness against hospitalisations and deaths during the Omicron BA.2.86/JN.1 period among older adults in seven European countries: A VEBIS-EHR network study. Expert Rev Vaccines. 2024 Jan-Dec;23(1):1085-1090. 10.1080/14760584.2024.2428800 1744-8395 1476-0584 Expert review of vaccines 39535047 https://hdl.handle.net/20.500.12105/25940 COVID-19 SARS-CoV-2 Cohort design Electronic health records Hospitalization Multi-country study Vaccine effectiveness Monovalent XBB.1.5 COVID-19 vaccine effectiveness against hospitalisations and deaths during the Omicron BA.2.86/JN.1 period among older adults in seven European countries: A VEBIS-EHR network study