Seasonal influenza vaccination trends from 2007-2011 in privately insured children and adults in the United States

Abstract

Background: To ensure adequate protection from seasonal influenza in the US, the Advisory Committee on Immunization Practices recommends vaccination of all persons aged 6 months or older, with rare exceptions. It also advises starting vaccination as soon as available and continuing throughout the influenza season. This study examined US seasonal vaccination trends during five consecutive influenza seasons in privately-insured children and adults.

Methods: This retrospective, observational cohort study examined trends in influenza vaccination during the 2007-2008 through 2011-2012 influenza seasons using administrative claims data from a large national insurer.

Results: The size of analysis population ranged from 1144,098 to 1245,487 (children, ≥6 months-17 years of age) and from 3931,622 to 4158,223 (adults, 18-64 years of age). Vaccination frequency increased through 2010-2011, was most frequent in young children, and decreased with age. Vaccination rates were highest in the Northeast and lowest in the West and were higher in individuals with frequent outpatient office visits than in those with no or rare visits, with larger differences seen in children. Between 2007 and 2011, the use of preservative-free inactivated vaccine increased, the use of multidose vaccines containing preservatives decreased, and the use of live attenuated influenza vaccines increased among children 2-17 years of age. From 2007-2008 through 2009-2010, the timing of vaccination each year began earlier than the previous one; it remained stable from 2009-2010 through 2011-2012.

Conclusion: Annual influenza vaccination claims for privately-insured children and adults increased and shifted earlier from 2007 through 2009-2011. During the 2011-2012 influenza season, 25.4% of children aged 6 months-17 years and 12.3% of adults aged 18-64 years were vaccinated. Increasing influenza vaccination should remain a priority, and alternative venues for seasonal influenza vaccination should be considered in order to meet the Healthy People 2020 goal of 80% to 90% coverage among children.

Keywords: Adults; Children; Influenza; Private insurance; Vaccination.