We estimated the effectiveness of the adapted monovalent XBB.1.5 COVID-19 vaccines against PCR-confirmed SARS-CoV-2 hospitalisation during the BA.2.86/JN.1 lineage-predominant period using a multicentre test-negative case-control study in Europe. We included older adults (≥ 65 years) hospitalised with severe acute respiratory infection from November 2023 to May 2024. Vaccine effectiveness was 46% at 14-59 days and 34% at 60-119 days, with no effect thereafter. The XBB.1.5 COVID-19 vaccines conferred protection against BA.2.86 lineage hospitalisation in the first 4 months post-vaccination.

Cantacuzino National Military Medical Institute for Research and Development Bucharest Romania

Center for Vaccinology Ghent University and Ghent University Hospital Ghent Belgium

Clinic of Infectious Diseases and Dermatovenerology Institute of Clinical Medicine Medical Faculty Vilnius University Vilnius Lithuania

Consortium for Biomedical Research in Epidemiology and Public Health Madrid Spain

Croatian Institute of Public Health Zagreb Croatia

Department of Infection Control Ghent University Hospital Ghent Belgium

Department of Infectious Diseases Lithuanian University of Health Sciences Kaunas Lithuania

Dr Victor Babes Clinical Hospital of Infectious and Tropical Diseases Bucharest Romania

Epiconcept Paris France

Epidemiology Department National Health Institute Doutor Ricardo Jorge Lisbon Portugal

European Centre for Disease Prevention and Control Stockholm Sweden

Health Service Executive Health Protection Surveillance Centre Dublin Ireland

Infectious Disease Prevention and Control Unit Health Promotion and Disease Prevention Msida Malta

Infectious Diseases Department National Health Institute Doutor Ricardo Jorge Lisbon Portugal

Instituto de Salud Pública de Navarra IdiSNA Pamplona Spain

National Centre for Epidemiology Institute of Health Carlos 3 Madrid Spain

National Laboratory for Health Security Epidemiology and Surveillance Centre Semmelweis University Budapest Hungary

National Reference Centre for Influenza Robert Koch Institute Berlin Germany

Sub Directorate General of Surveillance and Response to Public Health Emergencies Public Health Agency of Catalonia Generalitat of Catalonia Barcelona Spain

University Hospital Brno Masaryk University Brno Czechia

Zobrazit více v PubMed

European Centre for Disease Prevention and Control (ECDC) , “Interim COVID‐19 Vaccination Coverage in the EU/EEA During the 2023–24 Season Campaigns,” (2024), https://www.ecdc.europa.eu/en/publications‐data/interim‐covid‐19‐vaccination‐coverage‐eueea‐during‐2023‐24‐season‐campaigns.

World Health Organization (WHO) , “Statement on the Antigen Composition of COVID‐19 Vaccines,” https://www.who.int/news/item/26‐04‐2024‐statement‐on‐the‐antigen‐composition‐of‐covid‐19‐vaccines.

World Health Organization (WHO) , “Updated Risk Evaluation of JN.1,” (2024), https://www.who.int/docs/default‐source/coronaviruse/15042024_jn1_ure.pdf?sfvrsn=8bd19a5c_7.

European Centre for Disease Prevention and Control (ECDC) , “Communicable Disease Threats Report,” 17–23 December 2023, week 51, (2023), https://www.ecdc.europa.eu/en/publications‐data/communicable‐disease‐threats‐report‐17‐23‐december‐2023‐week‐51.

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 3.0,” (2024), https://www.ecdc.europa.eu/en/publications‐data/core‐protocol‐ecdc‐studies‐covid‐19‐vaccine‐effectiveness‐3.

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, (July 2020), http://www.europarl.europa.eu/RegData/etudes/BRIE/2020/652725/IPOL_BRI(2020)652725_EN.pdf.

European Centre for Disease Prevention and Control (ECDC) , “European Respiratory Virus Surveillance Summary (ERVISS),” (2024), Week 39.

Antunes L., Mazagatos C., Martínez‐Baz I., et al., “Early COVID‐19 XBB.1.5 Vaccine Effectiveness Against Hospitalisation Among Adults Targeted for Vaccination, VEBIS Hospital Network, Europe, October 2023–January 2024,” (2024). PubMed PMC

Nunes B., Humphreys J., Nicolay N., et al., “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,” (2024). PubMed

Kirsebom F. C. M., Stowe J., Lopez Bernal J., Allen A., and Andrews N., “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,” Journal of Infection 89, no. 1 (2024): 106177. PubMed

Tartof S. Y., Slezak J. M., Puzniak L., et al., “Effectiveness of BNT162b2 XBB Vaccine Against XBB and JN.1 Sub‐Lineages,” Open Forum Infectious Diseases 11, no. 7 (2024): ofae370. PubMed PMC

Ma K. C., Surie D., Lauring A. S., et al., “Effectiveness of Updated 2023–2024 (Monovalent XBB.1.5) COVID‐19 Vaccination Against SARS‐CoV‐2 Omicron XBB and BA.2.86/JN.1 Lineage Hospitalization and a Comparison of Clinical Severity—IVY Network, 26 Hospitals, October 18, 2023–March 9, 2024,” (2024). PubMed

Huiberts A. J., Hoeve C. E., de Gier B., et al., “Effectiveness of Omicron XBB.1.5 Vaccine Against Infection With SARS‐CoV‐2 Omicron XBB and JN.1 Variants, Prospective Cohort Study, the Netherlands, October 2023 to January 2024,” Eurosurveillance 29, no. 10 (2024): 2400109. PubMed PMC

Moustsen‐Helms I. R., Bager P., Larsen T. G., et al., “Relative Vaccine Protection, Disease Severity, and Symptoms Associated With the SARS‐CoV‐2 Omicron Subvariant BA.2.86 and Descendant JN.1 in Denmark: A Nationwide Observational Study,” Lancet Infectious Diseases 24, no. 9 (2024): 964–973. PubMed

Hansen C. H., “Bias in Vaccine Effectiveness Studies of Clinically Severe Outcomes That Are Measured With Low Specificity: The Example of COVID‐19‐Related Hospitalisation,” Eurosurveillance 29, no. 7 (2024. Feb): 2300259. PubMed PMC