Decrease in the Uptake of Seasonal Influenza Vaccine in Persons Aged 65 Years and Older In Ireland since the 2009 Influenza A (H1N1) Pdm09 Pandemic.

In Ireland, there is year-on-year variation in the seasonal influenza vaccine uptake for people aged 65 years and older. We obtained aggregate vaccine uptake data (2004/05-2014/15) by area and age group and applied the 2011 relative deprivation score and GP-density by area. Using Poisson regression model, we estimated the associations between those variables and uptake before and after the 2009 pandemic. After adjusting for age, deprivation status and GP-density, overall persons aged ?65 years were less likely to receive the vaccine after the pandemic compared to before (RR=0.89, 95%CI: 0.82-0.96). Uptake increased with age; both those in the 70-74 and ?75 year age groups were more likely to receive the vaccine compared to those aged 65-69 years (RR=1.18, 95%CI:1.14-1.24; RR=1.34, 95%CI:1.28-1.39 respectively). Qualitative studies should be undertaken to explore whether changes in public perception on risks of the disease and the vaccine and/or public funding and policy influenced the uptake.