Trends in influenza vaccination coverage rates in South Korea from 2005 to 2014: Effect of public health policies on vaccination behavior

Abstract Background Influenza is a major cause of morbidity and mortality worldwide. Annual vaccination is effective in its prevention and is recommended especially in susceptible populations such as the elderly over 65 years, children younger than 5, pregnant women, and people with chronic diseases. Overall, South Korea has a high vaccination rate owing to its National Immunization Program, although the method and extent of its coverage varies among the target subgroups. The aim of this study is to assess the trend of influenza vaccination coverage between 2005 and 2014 in South Korea to address the influence of sociodemographic and disease factors on vaccination behavior. Also, we aim to compare the vaccination coverage of target subgroups and evaluate the effect of relevant policies to provide suggestions for their improvement. Methods A total of 61,036 respondents from the Korea National Health and Nutrition Examination Surveys III to VI were included. Results The total influenza vaccination coverage increased from 38.0% in 2005 to 44.1% in 2014. Vaccination coverage was higher among the elderly aged ≥65 years (range, 70.0–79.8%; p-for-trend Conclusion Influenza vaccination rates have steadily increased from 2005 to 2014 in South Korea. Disparities between target groups correspond to their financial coverage under the National Immunization Program, and financial aids remove the influence of high income on higher vaccination rates. Future vaccination policies should focus on pregnant women and people with chronic diseases.