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We conducted a multicentre hospital-based test-negative case–control study to measure the effectiveness of adapted bivalent COVID-19 mRNA vaccines against PCR-confirmed SARS-CoV-2 infection during the Omicron XBB lineage-predominant period in patients aged ≥ 60 years with severe acute respiratory infection from five countries in Europe. Bivalent vaccines provided short-term additional protection compared with those vaccinated > 6 months before the campaign: from 80% (95% CI: 50 to 94) for 14–89 days post-vaccination, 15% (95% CI: −12 to 35) at 90–179 days, and lower to no effect thereafter.


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  1. European Medicines Agency (EMA). Authorised COVID-19 vaccines. Amsterdam: EMA. [Accessed: 2 Nov 2023]. Available from: https://www.ema.europa.eu/en/human-regulatory/overview/public-health-threats/coronavirus-disease-covid-19/covid-19-medicines
  2. European Centre for Disease Prevention and Control (ECDC). Overview of the implementation of COVID-19 vaccination strategies and deployment plans in the EU/EEA. Stockholm: ECDC; 2023. Available from: https://www.ecdc.europa.eu/sites/default/files/documents/Overview-vaccination-strategies-COVID-19-8-September-2022.pdf
  3. European Centre for Disease Prevention and Control (ECDC). ECDC de-escalates BA.2, BA.4 and BA.5 from its list of variants of concern. Stockholm: ECDC; 2023. Available from: https://www.ecdc.europa.eu/en/news-events/ecdc-de-escalates-ba2-ba4-and-ba5-its-list-variants-concern
  4. European Centre for Disease Prevention and Control (ECDC). Core protocol for ECDC studies of COVID-19 vaccine effectiveness against hospitalisation with severe acute respiratory infection, laboratory-confirmed with SARS-CoV-2 or with seasonal influenza - Version 2.0. Stockholm: ECDC. 2023. Available from: https://www.ecdc.europa.eu/en/publications-data/core-protocol-ecdc-studies-covid-19-vaccine-effectiveness-against-0
  5. Peralta-Santos A. Assessment of COVID-19 surveillance case definitions and data reporting in the European Union. Briefing requested by the ENVI committee. Brussels: European Parliament; 2020. Available from: http://www.europarl.europa.eu/RegData/etudes/BRIE/2020/652725/IPOL_BRI(2020)652725_EN.pdf
  6. European Centre for Disease Prevention and Control (ECDC). Data on SARS-CoV-2 variants in the EU/EEA. Stockholm: ECDC; 2023. Available from: https://www.ecdc.europa.eu/en/publications-data/data-virus-variants-covid-19-eueea
  7. Fabiani M, Mateo-Urdiales A, Sacco C, Rota MC, Fotakis EA, Petrone D, et al. Relative effectiveness of bivalent Original/Omicron BA.4-5 mRNA vaccine in preventing severe COVID-19 in persons 60 years and above during SARS-CoV-2 Omicron XBB.1.5 and other XBB sublineages circulation, Italy, April to June 2023. Euro Surveill. 2023;28(32):2300397.  https://doi.org/10.2807/1560-7917.ES.2023.28.32.2300397  PMID: 37561053 
  8. Kirsebom FCM, Harman K, Lunt RJ, Andrews N, Groves N, Abdul Aziz N, et al. Vaccine effectiveness against hospitalisation estimated using a test-negative case-control study design, and comparative odds of hospital admission and severe outcomes with COVID-19 sub-lineages BQ.1, CH.1.1. and XBB.1.5 in England. Lancet Reg Health Eur. 2023;35(Oct):100755.  https://doi.org/10.1016/j.lanepe.2023.100755  PMID: 38115965 
  9. Lin DY, Xu Y, Gu Y, Zeng D, Sunny SK, Moore Z. Durability of bivalent boosters against Omicron subvariants. N Engl J Med. 2023;388(19):1818-20.  https://doi.org/10.1056/NEJMc2302462  PMID: 37043647 
  10. Rose AM, Nicolay N, Sandonis Martín V, Mazagatos C, Petrović G, Baruch J, et al. Vaccine effectiveness against COVID-19 hospitalisation in adults (≥ 20 years) during Omicron-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021 to 2022. Euro Surveill. 2023;28(47):2300187.  https://doi.org/10.2807/1560-7917.ES.2023.28.47.2300187  PMID: 37997665 
  11. European Centre for Disease Prevention and Control (ECDC). Interim public health considerations for COVID-19 vaccination roll-out during 2023. Stockholm: ECDC; 2023. Available from: https://www.ecdc.europa.eu/en/publications-data/interim-public-health-considerations-covid-19-vaccination-roll-out-during-2023
  12. Kirsebom FCM, Andrews N, Stowe J, Ramsay M, Lopez Bernal J. Duration of protection of ancestral-strain monovalent vaccines and effectiveness of bivalent BA.1 boosters against COVID-19 hospitalisation in England: a test-negative case-control study. Lancet Infect Dis. 2023;23(11):1235-43.  https://doi.org/10.1016/S1473-3099(23)00365-1  PMID: 37453440 

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