Summary: Children should receive most of their immunizations before they reach 19 months old. To monitor the extent to which this goal is met nationwide, the Centers for Disease Control and Prevention (CDC) has, since 1991, administered a supplement to the National Health Interview Survey. In 1994, CDC decided to centralize the collection of immunization coverage data for preschoolers in each state and some urban areas. That year, CDC initiated the National Immunization Survey, which was designed to produce current and comparable immunization coverage estimates for children aged 19 to 35 months in each state and 28 urban areas receiving CDC funds. Unlike the National Health Interview Survey, which is a face-to-face household survey, the National Immunization Survey is conducted by telephone. Although national, antigen-specific immunization rates are generally high, some areas remain at continued risk of disease outbreaks (sometimes called "pockets of need") because they have concentrations of children who have not received timely vaccinations. This report assesses (1) the cost of the National Immunization Survey, (2) the methods used by CDC to conduct the survey, and (3) the utility of the survey in identifying "pockets" of children in need of more timely immunization.
