One of the national health objectives is to increase to 95% the proportion of children aged <6 years who participate in fully operational population-based IIS.
[citation needed] A "fully operational" IIS includes 95% enrollment or higher of all catchment area children less than 6 years of age with 2 or more immunization encounters administered according to ACIP recommendations.
An IIS record also can be initiated by a health care provider at the time of a child's first immunization.
Such a population-based IIS can make it easier to carry out the demonstrably effective immunization strategies (e.g., reminder/recall, AFIX, and WIC linkages) and thereby decrease the resources needed to achieve and maintain high levels of coverage.
Records of these immunizations often are based on computerized information systems designed for other purposes, such as billing.