Trends in influenza vaccination behaviours – results from the CoPanFlu cohort, France, 2006 to 2011

Controversies over the effectiveness and safety of the pandemic influenza A(H1N1)pdm09 vaccine in 2009/10 may have altered the influenza vaccination coverage in France after the pandemic season. The purpose of this study was to determine whether the pandemic affected seasonal influenza vaccination behaviours in the general population by analysing vaccination behaviours from 2006/07 to 2011/12 among the 1,451 subjects of the Cohort for Pandemic Influenza (CoPanFlu) France. We found that vaccination behaviours in 2010/11 and 2011/12 significantly differed from behaviours before the pandemic, with the notable exception of the targeted risk groups for seasonal influenza-related complications. Among the population with no risk factors, the post-pandemic influenza vaccine coverage decreased, with people aged 15 to 24 years and 45 to 64 years being most likely to abandon vaccination. Therefore, this study documents a moderate negative effect of the 2009/10 pandemic episode on vaccination behaviours in the French metropolitan population that was apparent also in the following two seasons. Moreover, it does not exclude that the general trend of reduced vaccination has also affected certain targeted groups at high risk for complications.