Influenza vaccination coverage among adults in Korea: 2008-2009 to 2011-2012 seasons

The aim of this study was to examine seasonal and pandemic influenza vaccination coverage in adults from the 2008-2009 season to the 2011-2012 season, including pandemic and post-pandemic seasons in Korea. We collected data of self-reported vaccine use from the Korean Community Health Survey. We also collected information on socioeconomic status and health behaviors in subpopulations. We tested for linear trends among the data to investigate vaccine coverage before and after the pandemic; and multiple logistic regression analyses were performed to identify predictors of obtaining the influenza vaccination. The results revealed a steady increase in vaccination coverage in every subgroup during four consecutive seasons. The highest rate of vaccine coverage (43.6%) occurred two years after the pandemic. Factors associated with vaccine receipt were: older age; lower education level; lower income; and health behaviors such as regular walking and receiving a health check-up. Smoking and drinking alcohol were inversely associated with vaccination. Having a chronic health condition was also a strong predictor of vaccine receipt. Though vaccination coverage rates were high in high-risk groups; disparities in coverage rates were substantial; particularly in young adults. Interventions are needed to minimize the coverage gaps among subgroups and to improve overall vaccination rates.