Immunization registries are databases that allow the collection and consolidation of vaccination data from multiple health-care providers. They also make it possible to generate reminder and recall notifications and assess vaccination coverage in defined geographic areas. Immunization-information systems (IISs) are registries that have additional capabilities, such as vaccine management, adverse-event reporting, lifespan vaccination histories, and linkages with electronic data (CDC, 2005). According to a report of the National Vaccine Advisory Committee (NVAC), IISs have been demonstrated to improve immunization coverage, support vaccine safety, increase timeliness of immunization, and help in the study of immunization effectiveness in children (Hinman et al., 2007). IISs can also prevent unnecessary immunizations by giving providers a single source for patients’ immunization histories (Yawn et al., 1998), reduce “no-show” rates, reduce vaccine waste, save staff costs by avoiding manual review of multiple records, aid in the establishment of Healthcare Effectiveness Data and Information Set (HEDIS) performance measures, and avoid costs associated with the National Immunization Survey (NIS) (Bartlett et al., 2007).
The development of IISs began in 1993 when CDC started to award planning grants to develop registries in every state (CDC, 2001a). President Clinton established the national Childhood Immunization Initiative by directing the secretary of health and human services to work with states to build “an integrated immunization registry system.” That initiative led to the Initiative on Immunization Registries, which was spearheaded by the NVAC with support from CDC’s National Immunization Program and the Department of Health and Human Services National Vaccine Program Office (Bartlett et al., 2007). Since 1994, CDC’s National Center for Immunization and Respiratory Diseases (formerly the National Immunization Program) has provided funding to 64 grantees (all 50 states, 6 cities, and the US territories) through Section 317 of the Public Health Service Act for the development of IISs. From 1994 through 2001, $181.3 million was allocated by CDC, and an additional $20 million was provided by the Robert Wood Johnson Foundation (CDC, 2001a). Only one state had reported no efforts to develop and implement an IIS as of December 31, 2005 (Hinman et al., 2007). However, three other states did not report to CDC in 2005 the percentage of children younger than 6 years old who participated in an IIS, and this might indicate inadequacy of IISs in those states.
CDC has indicated a commitment to support the continued development and expansion of state and community IISs (CDC, 2008b) and has a goal of including more than 95% of children under 6 years old in grantee IISs by 2010. To address wide variation in the performance of IISs nationally, CDC required detailed business plans from grantees in 2006 to