An estimated 5.1 million children in the U.S. had asthma, the most common chronic disease of childhood, in 2019.1 Half of children with asthma do not have well-controlled disease, resulting in hospitalizations, emergency department visits, missed school days, lower quality of life and missed workdays for parents.2 Children in lower-income, Black, and Puerto Rican communities who have asthma receive disproportionately lower quality of care and have worse health outcomes.3 Annual influenza vaccination has been recommended as part of a comprehensive strategy for preventing asthma-associated morbidity for more than 30 years.4, 5 Although influenza vaccination rates have increased overall during this time period, rates remain well below the Healthy People 2030 target of 70%.6 These rates remain low despite interventions to address barriers to influenza vaccine uptake in this population.7, 8 In addition to the suboptimal vaccination rates identified, these studies have also identified potential barriers to vaccination at multiple system levels. Examples of potential barriers identified include parent lack of awareness of recommendations, concerns about side effects, and trust in physician, continuity of care with a primary care clinician, provider lack of awareness of recommendations, and lack of systems for identifying children in need of vaccination and for tracking vaccination.9

Prior studies of influenza vaccine rates for children with asthma have largely focused on children insured by Medicaid10, 11, 12, 13 because of the high prevalence of children with higher risk for poor asthma outcomes in the Medicaid population. However, we are aware of no recent studies that have compared vaccination rates for privately insured children with asthma to rates for Medicaid-insured children using insurance claims data for a large population, a potentially important and actionable inequity in preventive asthma care.14 Additionally, recent policy changes increasing availability of influenza vaccination have the potential to affect vaccination rates for children with asthma. Massachusetts began allowing retail pharmacies to administer vaccinations to children aged nine years and older in May 2017.15

This study’s objective was to compare influenza vaccine rates for children insured by Medicaid to privately insured children in Massachusetts over the 2015-2018 period and to identify patterns of location of care that may help to identify opportunities for improving influenza vaccination rates for children with asthma as well as potential barriers.