U.S. children living in and near poverty: risk of vaccine-preventable diseases.
BACKGROUND
Poverty and factors associated with poverty are strong and persistent barriers to childhood immunization. Substantive differences in coverage with basic vaccinations have been consistently observed over time between children living in poverty and those who are not.


METHODS
The National Immunization Survey (NIS) uses a random-digit-dialing sample of telephone numbers in each state and in 28 urban areas. The NIS provides vaccination coverage information representative of all U.S. children aged 19 to 35 months. We categorized children in the NIS using Bureau of Census categories of poverty as follows: "above poverty" for household income > or = 125% of the federal poverty threshold for the household's size and composition; "near poverty," 100% to <125% of the poverty threshold; "intermediate poverty," 50% to <100% of the poverty threshold; and "severe poverty," <50% of the poverty threshold. We described coverage with basic vaccinations from 1996 through 1999 by poverty category and compare coverage between children in poverty and above poverty.


RESULTS
From 1996 to 1999, estimated vaccination coverage with the basic vaccine series was consistently higher among children living above the poverty level than all other children. The difference in estimated vaccination coverage between children living in severe poverty and those living above poverty was 13.6 percentage points in 1996, and 10.0 percentage points in 1999. Vaccination coverage with the series 4:3:1:3 among children living in near poverty was similar to that of children living in poverty (74.7% vs 73.3%, p=0.52). Estimated vaccination coverage increased significantly (p<0.05) between 1996 and 1999 for most antigens among children living above poverty and among those living in intermediate and severe poverty. Vaccination coverage among children living in poverty increased significantly (p<0.05) between 1996 and 1999 in 1 of the 28 urban areas in the NIS.


CONCLUSIONS
Low vaccination coverage among children living in and near poverty is a persistent problem in the United States. Additional efforts are needed to improve coverage.
Klevens
R M
RM
National Immunization Program, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. rmk2@cdc.gov
Luman
E T
ET
D002675:Child, Preschool; D019538:Health Care Surveys; D006801:Humans; D017589:Immunization Programs / Q000191:economics* / Q000706:statistics & numerical data*; D007223:Infant; D009313:National Health Programs; D011203:Poverty; D012959:Socioeconomic Factors; D014481:United States; D014611:Vaccination / Q000191:economics / Q000706:statistics & numerical data