{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T12:24:53Z","timestamp":1768566293235,"version":"3.49.0"},"posted":{"date-parts":[[2024,7,7]]},"group-title":"Infectious Diseases (except HIV\/AIDS)","reference-count":16,"publisher":"openRxiv","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2024,7,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>Monovalent XBB.1.5 vaccine was administered among those aged \u226565 years in EU\/EEA countries in autumn 2023; soon after SARS-Cov-2 BA.2.86\/JN.1 lineages became dominant. We aimed to estimate XBB.1.5 vaccine effectiveness (VE) against COVID-19-related hospitalisations and deaths during a period of BA.2.86\/JN.1 predominance using a European multi-country study.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>We linked electronic health record data to create historical cohorts in Belgium, Denmark, Italy, Navarre (Spain), Norway, Portugal and Sweden. We included individuals aged \u226565 years eligible for the autumnal 2023 COVID-19 vaccine with at least a primary series. Follow-up started when \u226580% of country-specific sequenced viruses were BA.2.86\/JN.1 lineages (4\/12\/23 to 08\/01\/24) and ended 25\/02\/2024. At study site level, we estimated the overall vaccine confounder-adjusted (for age, sex, country\u2019s region, comorbidities and previous booster doses) hazard ratio (aHR) of COVID-19 hospitalisations and deaths between individuals with \u226514 days after vaccination and individuals unvaccinated in autumn 2023, as well as by time since vaccination and stratified by age groups. VE was estimated as (1-pooled aHR)x100 with a random effects model.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>XBB.1.5 VE against COVID-19 hospitalisations was 50% (95%CI: 45 to 55) and 41% (95%CI: 35 to 46) in 65-79-year-olds and in \u226580-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 respective outcome declined in all age group over time.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusion<\/jats:title>\n                  <jats:p>Monovalent XBB.1.5 vaccine had a moderate protective effect against severe COVID-19 likely caused by BA.2.86\/JN.1 during the 2023\/2024 winter, among persons aged \u226565.<\/jats:p>\n                <\/jats:sec>","DOI":"10.1101\/2024.07.04.24309832","type":"posted-content","created":{"date-parts":[[2024,7,7]],"date-time":"2024-07-07T13:10:13Z","timestamp":1720357813000},"source":"Crossref","is-referenced-by-count":2,"title":["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"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6230-7209","authenticated-orcid":false,"given":"Baltazar","family":"Nunes","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0009-0004-3789-8309","authenticated-orcid":false,"given":"James","family":"Humphreys","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5916-7855","authenticated-orcid":false,"given":"Nathalie","family":"Nicolay","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5637-4613","authenticated-orcid":false,"given":"Toon","family":"Braeye","sequence":"additional","affiliation":[]},{"given":"Izaak","family":"Van Evercooren","sequence":"additional","affiliation":[]},{"given":"Christian Holm","family":"Hansen","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1143-511X","authenticated-orcid":false,"given":"Ida Rask","family":"Moustsen-Helms","sequence":"additional","affiliation":[]},{"given":"Chiara","family":"Sacco","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5893-7117","authenticated-orcid":false,"given":"Massimo","family":"Fabiani","sequence":"additional","affiliation":[]},{"given":"Jes\u00fas","family":"Castilla","sequence":"additional","affiliation":[]},{"given":"Iv\u00e1n","family":"Mart\u00ednez-Baz","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5898-2778","authenticated-orcid":false,"given":"Hinta","family":"Meijerink","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1849-1499","authenticated-orcid":false,"given":"Ausenda","family":"Machado","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5033-9115","authenticated-orcid":false,"given":"Patricia","family":"Soares","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0654-4530","authenticated-orcid":false,"given":"Rickard","family":"Ljung","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6812-0971","authenticated-orcid":false,"given":"Nicklas","family":"Pihlstr\u00f6m","sequence":"additional","affiliation":[]},{"given":"Anthony","family":"Nardone","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6575-3439","authenticated-orcid":false,"given":"Sabrina","family":"Bacci","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1412-3012","authenticated-orcid":false,"given":"Susana","family":"Monge","sequence":"additional","affiliation":[]}],"member":"54368","reference":[{"key":"2024070923450805000_2024.07.04.24309832v1.1","unstructured":"European Centre for Disease Prevention and Control. Interim COVID-19 vaccination coverage in the EU\/EEA during the 2023\u201324 season campaigns [Internet]. ECDC; 2024 [cited 2024 May 28]. Available from: https:\/\/www.ecdc.europa.eu\/en\/publications-data\/interim-covid-19-vaccination-coverage-eueea-during-2023-24-season-campaigns"},{"key":"2024070923450805000_2024.07.04.24309832v1.2","unstructured":"European Centre for Disease Prevention and Control. Communicable disease threats report, 17-23 December 2023, week 51. ECDC; 2023."},{"key":"2024070923450805000_2024.07.04.24309832v1.3","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(23)00746-6"},{"issue":"4","key":"2024070923450805000_2024.07.04.24309832v1.4","doi-asserted-by":"crossref","first-page":"e13292","DOI":"10.1111\/irv.13292","article-title":"Effectiveness of XBB.1.5 Monovalent COVID-19 Vaccines During a Period of XBB.1.5 Dominance in EU\/EEA Countries, October to November 2023: A VEBIS-EHR Network Study","volume":"18","year":"2024","journal-title":"Influenza Other Respir Viruses"},{"key":"2024070923450805000_2024.07.04.24309832v1.5","doi-asserted-by":"crossref","unstructured":"Caffrey AR , Appaneal HJ , Lopes VV , Puzniak L , Zasowski EJ , Jodar L , et al. Effectiveness of BNT162b2 XBB vaccine in the US Veterans Affairs Healthcare System. medRxiv. 2024 Jan 1;2024.04.05.24305063.","DOI":"10.1101\/2024.04.05.24305063"},{"key":"2024070923450805000_2024.07.04.24309832v1.6","doi-asserted-by":"crossref","unstructured":"Tartof SY , Slezak JM , Puzniak L , Frankland TB , Ackerson BK , Jodar L , et al. Effectiveness of BNT162b2 XBB Vaccine against XBB and JN.1 Sub-lineages. medRxiv. 2024 Jan 1;2024.05.04.24306875.","DOI":"10.1101\/2024.05.04.24306875"},{"issue":"2","key":"2024070923450805000_2024.07.04.24309832v1.7","doi-asserted-by":"crossref","first-page":"e70","DOI":"10.1016\/S1473-3099(23)00744-2","article-title":"Fast evolution of SARS-CoV-2 BA.2.86 to JN.1 under heavy immune pressure","volume":"24","year":"2024","journal-title":"Lancet Infect Dis"},{"issue":"1","key":"2024070923450805000_2024.07.04.24309832v1.8","doi-asserted-by":"crossref","first-page":"106177","DOI":"10.1016\/j.jinf.2024.106177","article-title":"Effectiveness of autumn 2023 COVID-19 vaccination and residual protection of prior doses against hospitalisation in England, estimated using a test-negative case-control study","volume":"89","year":"2024","journal-title":"J Infect"},{"key":"2024070923450805000_2024.07.04.24309832v1.9","doi-asserted-by":"crossref","unstructured":"Sent\u00eds A , Kislaya I , Nicolay N , Meijerink H , Starrfelt J , Mart\u00ednez-Baz I , et al. Estimation of COVID-19 vaccine effectiveness against hospitalisation in individuals aged \u2265 65 years using electronic health registries; a pilot study in four EU\/EEA countries, October 2021 to March 2022. Euro Surveill Bull Eur Sur Mal Transm Eur Commun Dis Bull. 2022 Jul;27(30).","DOI":"10.2807\/1560-7917.ES.2022.27.30.2200551"},{"issue":"11","key":"2024070923450805000_2024.07.04.24309832v1.10","doi-asserted-by":"crossref","first-page":"e13195","DOI":"10.1111\/irv.13195","article-title":"Monitoring COVID-19 vaccine effectiveness against COVID-19 hospitalisation and death using electronic health registries in \u226565 years old population in six European countries, October 2021 to November 2022","volume":"17","year":"2023","journal-title":"Influenza Other Respir Viruses"},{"key":"2024070923450805000_2024.07.04.24309832v1.11","first-page":"2300670","article-title":"Relative vaccine effectiveness against COVID-19 hospitalisation in persons aged \u2265 65 years: results from a VEBIS network, Europe, October 2021 to July 2023","volume":"29","year":"2024","journal-title":"Eurosurveillance"},{"key":"2024070923450805000_2024.07.04.24309832v1.12","unstructured":"European Centre for Disease Prevention and Control. Protocol for a COVID-19 vaccine effectiveness estimation using health data registries, VEBIS multi-country study \u2013 Version 2.0 [Internet]. ECDC; 2024 [cited 2024 May 28]. Available from: https:\/\/www.ecdc.europa.eu\/en\/publications-data\/protocol-covid-19-vaccine-effectiveness-estimation-using-health-data-registries"},{"key":"2024070923450805000_2024.07.04.24309832v1.13","unstructured":"European Centre for Disease Prevention and Control. European Respiratory Virus Surveillance Summary (ERVISS) [Internet]. 2024 [cited 2024 Jun 27]. Available from: https:\/\/erviss.org\/"},{"key":"2024070923450805000_2024.07.04.24309832v1.14","doi-asserted-by":"publisher","DOI":"10.1002\/sim.1186"},{"key":"2024070923450805000_2024.07.04.24309832v1.15","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(24)00220-2"},{"key":"2024070923450805000_2024.07.04.24309832v1.16","doi-asserted-by":"crossref","unstructured":"Hansen CH . Bias in vaccine effectiveness studies of clinically severe outcomes that are measured with low specificity: the example of COVID-19-related hospitalisation. Euro Surveill Bull Eur Sur Mal Transm Eur Commun Dis Bull. 2024 Feb;29(7).","DOI":"10.2807\/1560-7917.ES.2024.29.7.2300259"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1101\/2024.07.04.24309832","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T20:05:31Z","timestamp":1768507531000},"score":1,"resource":{"primary":{"URL":"http:\/\/medrxiv.org\/lookup\/doi\/10.1101\/2024.07.04.24309832"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,7,7]]},"references-count":16,"URL":"https:\/\/doi.org\/10.1101\/2024.07.04.24309832","relation":{"is-preprint-of":[{"id-type":"doi","id":"10.1080\/14760584.2024.2428800","asserted-by":"subject"}]},"subject":[],"published":{"date-parts":[[2024,7,7]]},"subtype":"preprint"}}