{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T08:04:25Z","timestamp":1784275465702,"version":"3.55.0"},"reference-count":37,"publisher":"Cambridge University Press (CUP)","license":[{"start":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T00:00:00Z","timestamp":1766707200000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0"}],"content-domain":{"domain":["cambridge.org"],"crossmark-restriction":true},"short-container-title":["Epidemiol. Infect."],"published-print":{"date-parts":[[2026]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>We estimated the vaccine effectiveness (VE) of second monovalent and bivalent booster vaccines containing Omicron BA.1 or BA.4\/BA.5 and the protection conferred by natural immunity against SARS-CoV-2 infection in Luxembourg. We conducted a test-negative case\u2013control study among residents aged 60\u00a0years or older by integrating national socio-demographic, COVID-19 vaccination, and testing data, achieving full population coverage. Using conditional logistic regression, we estimated absolute and relative VE of monovalent and bivalent boosters and natural immunity from prior infection. Our analysis included 5,390 test-positive cases and 11,048 test-negative controls matched by week of testing between September 2022 and April 2023. Absolute VE for monovalent and bivalent boosters decreased from 64.8% and 66.6% in the first month to 1.5% and 16.5% after 5\u20136\u00a0months, respectively. The bivalent was superior to the monovalent booster only in individuals without natural immunity (relative VE 25.7%, 95% confidence interval 11.4%; 37.7%). Natural immunity lasted longer than vaccine-induced immunity with 80.7% protected at 4\u20138\u00a0months and 44.9% at 15\u201325\u00a0months post-infection. Both second booster vaccines provided temporary protection against SARS-CoV-2 infection; bivalent boosters offered a slight benefit over monovalent boosters. Natural immunity appears to confer longer-lasting protection.<\/jats:p>","DOI":"10.1017\/s0950268825100903","type":"journal-article","created":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T04:12:26Z","timestamp":1766722346000},"update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":0,"title":["Protection from second booster vaccines and natural immunity against SARS-CoV-2 infections, 2022\u20132023"],"prefix":"10.1017","volume":"154","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3045-3030","authenticated-orcid":false,"given":"Dritan","family":"Bejko","sequence":"first","affiliation":[{"name":"Universiteit Maastricht School of Nutrition and Translational Research in Metabo"},{"name":"Health Directorate, Luxembourg"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anne","family":"Vergison","sequence":"additional","affiliation":[{"name":"Health Directorate, Luxembourg"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saverio","family":"Stranges","sequence":"additional","affiliation":[{"name":"Western University Schulich School of Medicine & Dentistry"},{"name":"University of Western Ontario Schulich School of Medicine & Dentistry"},{"name":"Western University Schulich School of Medicine & Dentistry"},{"name":"University of Naples Federico II"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0717-9835","authenticated-orcid":false,"given":"Jo\u00ebl","family":"Mossong","sequence":"additional","affiliation":[{"name":"Health Directorate, Luxembourg"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maurice","family":"Zeegers","sequence":"additional","affiliation":[{"name":"Maastricht University School of Nutrition and Translational Research in Metaboli"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2025,12,26]]},"reference":[{"key":"S0950268825100903_r1","volume-title":"\u00c9valuation Des r\u00e9ponses Au COVID-19 du Luxembourg","year":"2022"},{"key":"S0950268825100903_r15","doi-asserted-by":"publisher","DOI":"10.24171\/j.phrp.2024.0063"},{"key":"S0950268825100903_r6","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(24)00077-X"},{"key":"S0950268825100903_r31","doi-asserted-by":"publisher","DOI":"10.1016\/j.xcrm.2021.100354"},{"key":"S0950268825100903_r9","doi-asserted-by":"publisher","DOI":"10.2807\/1560-7917.ES.2023.28.7.2300087"},{"key":"S0950268825100903_r24","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiad419"},{"key":"S0950268825100903_r22","doi-asserted-by":"publisher","DOI":"10.1093\/ije\/dyad114"},{"key":"S0950268825100903_r21","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2024.05.059"},{"key":"S0950268825100903_r12","doi-asserted-by":"publisher","DOI":"10.3389\/fmed.2023.1322396"},{"key":"S0950268825100903_r29","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(22)00143-8"},{"key":"S0950268825100903_r28","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-023-47043-6"},{"key":"S0950268825100903_r19","unstructured":"[19] World Health Organization (2022) Public health surveillance for COVID-19: interim guidance."},{"key":"S0950268825100903_r10","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2023.07.071"},{"key":"S0950268825100903_r23","doi-asserted-by":"publisher","DOI":"10.15585\/mmwr.mm715152e2"},{"key":"S0950268825100903_r7","volume-title":"Respiratory Virus Surveillance Report","year":"2023"},{"key":"S0950268825100903_r34","volume-title":"Loi du 17 Juillet 2020 Portant Introduction de Mesures de Lutte Contre la Pandemie Covid-19 Version Consolidee Applicable au 11\/02\/2022","year":"2022"},{"key":"S0950268825100903_r35","doi-asserted-by":"publisher","DOI":"10.1097\/EDE.0000000000001366"},{"key":"S0950268825100903_r2","unstructured":"[2] European Centre for Disease Prevention and Control. Data on COVID-19 vaccination in the EU\/EEA. https:\/\/qap.ecdc.europa.eu\/public\/extensions\/COVID-19\/vaccine-tracker.html#uptake-tab (accessed 08 January 2026)"},{"key":"S0950268825100903_r37","doi-asserted-by":"publisher","DOI":"10.1093\/aje\/kwac203"},{"key":"S0950268825100903_r17","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(22)00271-7"},{"key":"S0950268825100903_r32","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2020.611337"},{"key":"S0950268825100903_r11","doi-asserted-by":"publisher","DOI":"10.1093\/ofid\/ofad475"},{"key":"S0950268825100903_r26","doi-asserted-by":"publisher","DOI":"10.1080\/21645515.2024.2335052"},{"key":"S0950268825100903_r16","unstructured":"[16] M\u00e9morial A624 (2020) Loi du 17 juillet 2020 sur les mesures de lutte contre la pand\u00e9mie Covid-19. 7622."},{"key":"S0950268825100903_r20","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmi.2020.11.028"},{"key":"S0950268825100903_r30","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2021.01.007"},{"key":"S0950268825100903_r14","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0262169"},{"key":"S0950268825100903_r27","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-024-48414-x"},{"key":"S0950268825100903_r3","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa2108891"},{"key":"S0950268825100903_r18","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-021-27410-5"},{"key":"S0950268825100903_r8","doi-asserted-by":"publisher","DOI":"10.3346\/jkms.2023.38.e396"},{"key":"S0950268825100903_r36","doi-asserted-by":"publisher","DOI":"10.15585\/mmwr.mm7112e1"},{"key":"S0950268825100903_r33","doi-asserted-by":"publisher","DOI":"10.2147\/CLEP.S468572"},{"key":"S0950268825100903_r25","doi-asserted-by":"publisher","DOI":"10.2807\/1560-7917.ES.2023.28.48.2300173"},{"key":"S0950268825100903_r13","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2021.770727"},{"key":"S0950268825100903_r5","first-page":"1279","article-title":"A bivalent omicron-containing booster vaccine against Covid-19","volume":"387","author":"Chalkias","year":"2022","journal-title":"New England Journal of Medicine Massachusetts Medical Society"},{"key":"S0950268825100903_r4","doi-asserted-by":"publisher","DOI":"10.15585\/mmwr.mm7104e3"}],"container-title":["Epidemiology and Infection"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0950268825100903","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T07:12:52Z","timestamp":1784272372000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0950268825100903\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,26]]},"references-count":37,"alternative-id":["S0950268825100903"],"URL":"https:\/\/doi.org\/10.1017\/s0950268825100903","relation":{},"ISSN":["0950-2688","1469-4409"],"issn-type":[{"value":"0950-2688","type":"print"},{"value":"1469-4409","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,26]]},"assertion":[{"value":"\u00a9 The Author(s), 2025. Published by Cambridge University Press","name":"copyright","label":"Copyright","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}},{"value":"This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives licence (http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0), which permits non-commercial re-use, distribution, and reproduction in any medium, provided that no alterations are made and the original article is properly cited. The written permission of Cambridge University Press or the rights holder(s) must be obtained prior to any commercial use and\/or adaptation of the article.","name":"license","label":"License","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}},{"value":"This content has been made available to all.","name":"free","label":"Free to read"}],"article-number":"e10"}}