Influenza vaccine effectiveness

Vaccine effectiveness is an estimate of the likelihood that a vaccine prevents influenza infection when used in everyday practice. To establish how well influenza vaccines work each season, influenza vaccine effectiveness is measured in observational studies.

In EU/EEA, the ECDC founded network I-MOVE (Influenza - Monitoring Vaccine Effectiveness) is responsible for measuring the vaccine effectiveness.

The studies provide country-specific and pooled effectiveness results for influenza vaccines authorised and used in EU/EEA Member States. The results are presented by age group and by different influenza vaccine strain. Since the influenza season 2012/13 results from observational studies assessing LAIV (Live attenuated influenza vaccine) used in children are available.

In general, a vaccine effectiveness of ~30-60% has been estimated for the three different influenza A (H1N1, H3N2) and B strains (Victoria or Yamagata lineages).

In Europe influenza vaccine effectiveness studies were initiated by ECDC and have been followed systematically since the influenza season 2008/2009.

Table: Overview of articles on effectiveness of inactivated seasonal influenza vaccines estimated in multi-center studies conducted by the I-MOVE network in Europe

Season  Author  Article
Season 2016-17 Kissling et al Early 2016/17 vaccine effectiveness estimates against influenza A(H3N2): I-MOVE multicentre case control studies at primary care and hospital levels in Europe.
Season 2015-16 Kissling et al 2015/16 I-MOVE/I-MOVE+ multicentre case control study in Europe: moderate vaccine effectiveness estimates against influenza A(H1N1)pdm09 and low estimates against lineage mismatched influenza B among children
Season 2014-2015 Valenciano et al Vaccine effectiveness in preventing laboratory-confirmed influenza in primary care patients in a season of co-circulation of influenza A(H1N1)pdm09, B and drifted A(H3N2), I-MOVE Multicentre Case-Control Study, Europe 2014/15.
Season 2013-2014 Valenciano et al The European I-MOVE Multicentre 2013-2014 Case-Control Study.  Homogeneous moderate influenza vaccine effectiveness against A(H1N1)pdm09 and heterogeneous results by country against A(H3N2).
Season 2012-2013 Kissling et al Influenza vaccine effectiveness estimates in Europe in a season with three influenza type/subtypes circulating: the I-MOVE multicenter case-control study, influenza  season 2012/13
Season 2011-2012 Kissling et al

Low and decreasing vaccine effectiveness against influenza A(H3) in 2011/12 among vaccination target groups in Europe: results from the I-MOVE multicentre case–control study

Season 2010-2011 Kissling et al Overall and stratified estimates of influenza vaccine effectiveness in Europe for the season 2010-2011
Season 2009-2010 Valenciano M et al Estimates of Pandemic Influenza Vaccine Effectiveness in       Europe, 2009-2010: Results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE)     Multicenter Case-Control Study.
Season 2008-2009 Kissling et al I-MOVE” towards monitoring seasonal and pandemic influenza accine effectiveness: lessons learnt from a pilot multi-centric case-control study in Europe 2008-9  


The live attenuated influenza vaccines used in paediatric programmes in Finland, Germany and United Kingdom have also been evaluated:

ECDC Study protocols for influenza vaccine effectiveness studies


Protocols for case-control studies to measure influenza vaccine effectiveness in the EU and EEA Member States

Technical guidance -


Protocols for cohort database studies to measure influenza vaccine effectiveness in the EU and EEA Member States

Technical guidance -


Protocol for cluster investigations to measure influenza vaccine effectiveness in the EU/EEA

Technical guidance -

See all updates on vaccine defectiveness


Flu Awareness Week, 5-9 October 2020

5 Oct 2020 - 9 Oct 2020

Peer-Reviewed Publication

Effectiveness of influenza vaccine against influenza A in Europe in seasons of different A(H1N1)pdm09 and the same A(H3N2) vaccine components (2016–17 and 2017–18)

Dec 2019


Flu Awareness Week, 21-25 October 2019

21 Oct 2019 - 25 Oct 2019


Flu Awareness Week, 22 – 26 October 2018

22 Oct 2018 - 26 Oct 2018


Low uptake of seasonal influenza vaccination in Europe may jeopardise capacity to protect people in next pandemic

Press release -