Influenza vaccine effectiveness

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

In Europe influenza vaccine effectiveness studies were initiated by ECDC and have been followed systematically since the influenza season 2008/2009 by a network of public health and academic researchers (I-MOVE). Results have been provided for inactivated influenza vaccines overall with no possibility to distinguish between different vaccine products. However, results have been presented by age group and by different influenza vaccine strain. 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). Since the influenza season 2012/13 results from observational studies assessing also LAIV used in children have been published.

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 publications on the topic


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

technical guidance, protocol -

All ECDC updates on vaccine effectiveness and efficacy

Dec 2014


Assessing seasonal influenza vaccine effectiveness

3 Dec 2014


Initial studies on seasonal influenza vaccine effectiveness for 2013/2014

ECDC comment -


Annual influenza vaccine effectiveness meeting 2013 – summary of discussions on obtained results and recommended future research focus

ECDC comment -


Lower than usual: early influenza vaccine effectiveness in parts of Europe in season 2011/12

ECDC comment -


Study shows decreased vaccine effectiveness of the seasonal influenza vaccine; ECDC Director urges to develop more effective vaccines

news -