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 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: