Surveillance Open Access
Like 0



Influenza A(H1N1)pdm09, A(H3N2) and B viruses were co-circulating in Europe between September 2019 and January 2020.


To provide interim 2019/20 influenza vaccine effectiveness (VE) estimates from six European studies, covering 10 countries and both primary care and hospital settings.


All studies used the test-negative design, although there were some differences in other study characteristics, e.g. patient selection, data sources, case definitions and included age groups. Overall and influenza (sub)type-specific VE was estimated for each study using logistic regression adjusted for potential confounders.


There were 31,537 patients recruited across the six studies, of which 5,300 (17%) were cases with 5,310 infections. Most of these (4,466; 84%) were influenza A. The VE point estimates for all ages were 29% to 61% against any influenza in the primary care setting and 35% to 60% in hospitalised older adults (aged 65 years and over). The VE point estimates against A(H1N1)pdm09 (all ages, both settings) was 48% to 75%, and against A(H3N2) ranged from −58% to 57% (primary care) and −16% to 60% (hospital). Against influenza B, VE for all ages was 62% to 83% (primary care only).


Influenza vaccination is of continued benefit during the ongoing 2019/20 influenza season. Robust end-of-season VE estimates and genetic virus characterisation results may help understand the variability in influenza (sub)type-specific results across studies.


Article metrics loading...

Loading full text...

Full text loading...



  1. European Centre for Disease Prevention and Control (ECDC). Seasonal influenza vaccination and antiviral use in EU/EEA Member States: Overview of vaccine recommendations for 2017-2018 and vaccination coverage rates for 2015-2016 and 2016-2017 influenza seasons. Stockholm: ECDC; Nov 2018. Available from: https://ecdc.europa.eu/sites/portal/files/documents/seasonal-influenza-antiviral-use-2018.pdf
  2. Department of Health/National Health Service (DoH/NHS). The flu immunisation programme 2013/14 – extension to children. London: DoH/NHS; 26 Jul 2013. Available from: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/225360/Children_s_flu_letter_2013.pdf
  3. World Health Organization (WHO). Recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season. Geneva: WHO; Feb 2019. Available from: https://www.who.int/influenza/vaccines/virus/recommendations/201902_recommendation.pdf?ua=1
  4. World Health Organization (WHO). Addendum to the recommended composition of influenza virus vaccines for use in the 2019-2020 northern hemisphere influenza season. Geneva: WHO; 21 Mar 2019. Available from: https://www.who.int/influenza/vaccines/virus/recommendations/201902_recommendation_addendum.pdf?ua=1
  5. European Centre for Disease Prevention and Control (ECDC)/World Health Organization Regional Office for Europe (WHO/Europe). Flu News Europe. Summary Week 04/2020 (20-26 January 2020). Stockholm/Geneva: ECDC/WHO/Europe; Jan 2020. Available from: https://flunewseurope.org/Archives
  6. European Union (EU). Epiconcept. I-MOVE + Protocol for hospital-based test negative case control studies to measure seasonal influenza vaccine effectiveness against influenza laboratory confirmed SARI hospitalisation among the elderly across the European Union and European Economic Area Member States. Brussels: EU; Jun 2016. Available from: https://docs.google.com/viewer?a=v&pid=sites&srcid=ZXBpY29uY2VwdC5mcnxpbW92ZXBsdXN8Z3g6Njg0NjQwM2QxZDRlM2JmMw
  7. European Union (EU). Generic protocol for the test negative design case control studies to measure pandemic and seasonal influenza vaccine effectiveness in the European Union and European Economic Area Member States. Brussels: EU; 2015. Available from: https://drive.google.com/file/d/0Byv9pYYPpY4PM25qSXczQ3g4T0E/view
  8. Jiménez-Jorge S, de Mateo S, Delgado-Sanz C, Pozo F, Casas I, Garcia-Cenoz M, et al. Estimating influenza vaccine effectiveness in Spain using sentinel surveillance data. Euro Surveill. 2015;20(28):21187.  https://doi.org/10.2807/1560-7917.ES2015.20.28.21187  PMID: 26212144 
  9. Pebody R, Warburton F, Ellis J, Andrews N, Potts A, Cottrell S, et al. Effectiveness of seasonal influenza vaccine for adults and children in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2015/16 end-of-season results. Euro Surveill. 2016;21(38):30348.  https://doi.org/10.2807/1560-7917.ES.2016.21.38.30348  PMID: 27684603 
  10. Emborg HD, Krause TG, Nielsen L, Thomsen MK, Christiansen CB, Skov MN, et al. Influenza vaccine effectiveness in adults 65 years and older, Denmark, 2015/16 - a rapid epidemiological and virological assessment. Euro Surveill. 2016;21(14):30189.  https://doi.org/10.2807/1560-7917.ES.2016.21.14.30189  PMID: 27101732 
  11. Fukushima W, Hirota Y. Basic principles of test-negative design in evaluating influenza vaccine effectiveness. Vaccine. 2017;35(36):4796-800.  https://doi.org/10.1016/j.vaccine.2017.07.003  PMID: 28818471 
  12. World Medical Association. World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects. JAMA. 2013;310(20):2191-4.  https://doi.org/10.1001/jama.2013.281053  PMID: 24141714 
  13. Peduzzi P, Concato J, Feinstein AR, Holford TR. Importance of events per independent variable in proportional hazards regression analysis. II. Accuracy and precision of regression estimates. J Clin Epidemiol. 1995;48(12):1503-10.  https://doi.org/10.1016/0895-4356(95)00048-8  PMID: 8543964 
  14. Covenay J. FIRTHLOGIT: Stata module to calculate bias reduction in logistic regression. Boston: Boston College Department of Economics; 2015.
  15. Skowronski DM, Zou M, Sabaiduc S, Murti M, Olsha R, Dickinson JA, et al. Interim estimates of 2019/20 vaccine effectiveness during early-season co-circulation of influenza A and B viruses, Canada, February 2020. Euro Surveill. 2020;25(7):2000103.  https://doi.org/10.2807/1560-7917.ES.2020.25.7.2000103  PMID: 32098644 
  16. Dawood FS, Chung JR, Kim SS, Zimmerman RK, Nowalk MP, Jackson ML, et al. Interim Estimates of 2019-20 Seasonal Influenza Vaccine Effectiveness - United States, February 2020. MMWR Morb Mortal Wkly Rep. 2020;69(7):177-82.  https://doi.org/10.15585/mmwr.mm6907a1  PMID: 32078591 
  17. Finnish Institute for Health & Welfare (THL). Terveyden ja hyvinvoinnin laitos. [Up-to-date influenza review, updated 11 February 2020]. Helsinki: THL; Feb 2020. Finnish. Available from: https://thl.fi/fi/web/infektiotaudit-ja-rokotukset/taudit-ja-torjunta/taudit-ja-taudinaiheuttajat-a-o/influenssa/ajantasainen-influenssakatsaus
  18. Smittskydd Stockholm. Säsongstatistik för influensa 2019/2020. [Seasonal statistics for influenza 2019/2020; week 6 2020. Stockholm: Smittskydd Stockholm; Feb 2020. Swedish. Available from: https://vardgivarguiden.se/globalassets/kunskapsstod/smittskydd/statistik/influensa/influensasasongen-2019-2020.pdf
  19. Kissling E, Rose A, Emborg H-D, Gherasim A, Pebody R, Pozo F, et al. Interim 2018/19 influenza vaccine effectiveness: six European studies, October 2018 to January 2019. Euro Surveill. 2019;24(8):1900121.  https://doi.org/10.2807/1560-7917.ES.2019.24.1900121  PMID: 30808440 
  20. European Centre for Disease Prevention and Control (ECDC). Surveillance report: Influenza virus characterisation. Stockholm: ECDC; Dec 2019. Available from: https://www.ecdc.europa.eu/sites/default/files/documents/influenza-virus-characterisation-december-2019.pdf
  21. Skowronski DM, Sabaiduc S, Leir S, Rose C, Zou M, Murti M, et al. Paradoxical clade- and age-specific vaccine effectiveness during the 2018/19 influenza A(H3N2) epidemic in Canada: potential imprint-regulated effect of vaccine (I-REV). Euro Surveill. 2019;24(46):1900585.  https://doi.org/10.2807/1560-7917.ES.2019.24.46.1900585  PMID: 31771709 
  22. Chen Z, Zhou H, Jin H. The impact of key amino acid substitutions in the hemagglutinin of influenza A (H3N2) viruses on vaccine production and antibody response. Vaccine. 2010;28(24):4079-85.  https://doi.org/10.1016/j.vaccine.2010.03.078  PMID: 20399830 
  23. Worldwide Influenza Centre. Report prepared for the WHO annual consultation on the composition of influenza vaccine for the northern hemisphere 2019-2020 [Internet]. London: The Francis Crick Institute; Feb 2019. Available from: www.crick.ac.uk/sites/default/files/2019-04/Crick%20VCMFeb2019%20report_toPost.pdf
  24. Worldwide Influenza Centre. Report prepared for the WHO annual consultation on the composition of influenza vaccines for the Southern Hemisphere 2019-2020. London: The Francis Crick Institute; Sep 2019. Available from: https://www.crick.ac.uk/sites/default/files/2019-10/CrickSH2019VCMreport.pdf
  25. World Health Organization (WHO). Recommended composition of influenza virus vaccines for use in the 2020-2021 northern hemisphere influenza season. Geneva: WHO; Feb 2020. Available from: https://www.who.int/influenza/vaccines/virus/recommendations/202002_recommendation.pdf?ua=1

Data & Media loading...

Comment has been disabled for this content
Submit comment
Comment moderation successfully completed
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error