Trends in early childhood vaccination coverage: progress towards US Healthy People 2010 goals

To evaluate trends in national vaccination coverage from 2000 to 2007 among children aged 19-35 months for at least four doses of diphtheria-tetanus-pertussis vaccine (4+DTaP), three doses of poliovirus vaccine (3+Polio), one dose of measles-mumps-rubella vaccine (1+MMR), three doses of Haemophilus influenzae type b vaccine (3+Hib), three doses of hepatitis B vaccine (3+HepB), one dose of Varicella vaccine (1+Var), and the standard vaccine series of these six vaccines (4:3:1:3:3:1). To predict vaccination coverage levels in 2008-2010 for those vaccines that have not yet reached the Healthy People 2010 coverage targets of 90% for individual vaccines and 80% for the vaccine series.

Data were analyzed for 167,086 children aged 19-35 months in the 2000-2007 National Immunization Survey. Vaccination coverage trends were analyzed with weighted least squares linear regression models. Nonlinear Weibull and logarithmic regression models were fitted to these past results, and extrapolation was used to predict vaccination coverage levels for 4+DTaP, 1+Var, and the 4:3:1:3:3:1 series from 2008 to 2010.

From 2000 to 2007, observed vaccination coverage increased significantly for four of the six vaccines and the standard vaccine series, and reached the 90% target for 3+Polio, 1+MMR, 3+Hib, and 3+HepB. Increases in coverage were not significant for 1+MMR and 3+Hib; however, coverage for these vaccines was consistently>90% throughout the study period. Both Weibull and logarithmic regression models predicted that coverage with 1+Var and the 4:3:1:3:3:1 series will surpass the 2010 target by 2008, while coverage with 4+DTaP will fall short of the target at 86% in 2010.

The United States is well on the way toward reaching most of the Healthy People 2010 objectives for early childhood vaccination coverage. Enhanced efforts are needed to ensure that these trends continue, and to increase coverage with 4+DTaP.