N C H S - National Immunization Survey, Overview (English)

Immunizing children against infectious disease has been a central mission, and a substantial success, for our national public health systems. During the 20th century the United States has seen the incidence of measles, pertussis, and diphtheria fall by more than 98%. This is due primarily to the use of vaccines that immunize children against these illnesses. But many children are still not adequately vaccinated, and levels of disease can be lowered much further.

The Childhood Immunization Initiative (CII) is one of many Federal, State, and local programs mounted to raise vaccination levels among young children. Initiated by President Clinton, the CII established a 1996 goal of increasing vaccination levels for 2-year-old children to at least 90% for measles-mumps-rubella, diphtheria and tetanus toxoids and pertussis vaccine, oral poliovirus vaccine, and Haemophilus influenzae type b vaccine. In addition, the CII established a goal for 1996 to increase vaccination levels for 2-year-old children to at least 70% for three or more doses of hepatitis B (Hep B) vaccine. Sponsored by the Centers for Disease Control and Prevention (CDC), the National Immunization Survey (NIS) is used to assess progress towards these goals. The study collects data by interviewing households in all 50 States, the District of Columbia, and 27 urban areas. The interviews are conducted by telephone with households selected by random chance. The NIS data provide current, population-based, State and local area estimates of vaccination coverage produced by a standard methodology. Each quarter, estimates of vaccination coverage levels are calculated and valid comparisons of State efforts to deliver vaccination services are made. As well as evaluating progress towards national vaccination goals, CDC uses the NIS data to identify States with the highest and lowest rates. To assure the accuracy and precision of the estimates, immunization data for surveyed children are also collected through a mail survey of their pediatricians, family physicians, and other health care providers. The parents and guardians of NIS-eligible children are asked during the telephone interview for consent to contact childrens' vaccination providers. In the past year, the NIS Provider Study Immunization History Questionnaire was sent to approximately 30,000 medical providers. Types of immunizations, dates of administration, and additional data about facility characteristics are requested from immunization providers identified during the telephone survey of households. The NIS estimates of vaccination coverage reflect a comparison of information provided by both immunization providers and households.

The NIS study has two parts:
1. A household telephone survey. This survey asks questions about childhood immunization for children 19-35 months of age and requests parental permission for contacting children's vaccination providers. Data are used primarily to monitor immunization coverage in the preschool population in 78 nonoverlapping geographic areas.
2. A survey of vaccination providers. This survey of doctors and other vaccination providers is conducted for study participants who have provided consent for this phase of the study.

The NIS is now conducted for the CDC by the National Opinion Research Center (NORC) at the University of Chicago. If you have any questions about the National Immunization Survey (NIS), please call toll free at 1-866-999-3340.