Timeliness of 2009 H1N1 vaccine coverage in a low-income pediatric and adolescent population.

Despite being at highest risk for 2009 H1N1 virus morbidity and mortality, many children were not immunized with the vaccine. Identification of factors that put certain children at higher risk for under-immunization could reveal populations who may need to be specifically targeted for vaccination interventions in future pandemics. Little is known about the prevalence of, or factors associated with, 2009 H1N1 vaccine coverage in low-income, urban pediatric populations. This study evaluated 2009 H1N1 vaccination coverage in 19,643 children aged 6months to 18years receiving care at one of five community clinics associated with an academic medical center in a low-income community. Any (≥1 dose) and full coverage (1 dose for children ≥10years old, 2 doses for those <10years) was determined as of December 1, 2009 and the end of vaccination period (June 30, 2010). Multivariable analyses were used to assess the impact of race/ethnicity, age, insurance, gender, and language on vaccine coverage and timeliness. By December 1, only 16.6% of children had received one dose, and 5.3% had full coverage. By the end of the vaccination period, 36.2% had received at least one H1N1 dose and 23.6% had full coverage. On multivariable analysis, older age, minority race/ethnicity, and private insurance were negatively associated with vaccination by December 1 and end of vaccination period, even after accounting for attendance at a clinic visit. In future pandemics, when timely receipt of a new vaccine in large populations may be imperative, general vaccination programs as well as special targeted education and vaccine reminders for these at risk groups may be warranted.