Historical Core Data Elements

Note: The IIS Core Data Elements have been updated as of 12/7/2012.  The 2013-2018 Core Data Elements supersede the 2007 IIS Recommended Core Data Elements and accompany revised IIS Functional Standards for 2013-2018.

Origin and Development of the Core Data Items

The original Immunization Information Systems (IIS) core data items were prepared in 1995 by CDC’s National Center for Immunization and Respiratory Diseases in consultation with the Immunization Grantee Working Group. It was reviewed by the National Vaccine Advisory Committee (NVAC), and recommendations of NVAC were incorporated. Contributions were also made by public health representatives and private providers. On February 5, 2007 NVAC approved a new set of core data items which were developed in consultation with CDC and the American Immunization Registry Association. The data items were published in the complete 2007 NVAC report [1.04 MB, 38 pages]

The Journal of Public Health Management and Practice published a summary of the complete report in the November/December 2007 edition.

Core Data Item Categories

The core data items fall into two categories: required and optional. These elements represent fundamental attributes necessary for identifying individuals and for describing immunization events.

  • Required elements are critical for record exchange purposes, client deduplication, vaccine management, immunization status evaluation, reminder / recall and data analysis or use purposes.
  • Optional core data elements are less important for record exchange. Some optional items (e.g., address) may be useful only at the local level.


The purpose of the core data element is to facilitate record exchange between IIS. It is imperative that, at a minimum, each IIS include in its database schema a method to receive and store all of the required core data elements, even if the IIS does not routinely collect the information. Thus, if an IIS receives a record from one system and subsequently transfers it to another, no required core data elements will be lost in the process. It is strongly recommended that IIS also collect data on all of the required core data elements for their own patients. Prospective implementation should begin on or before January 1, 2009 to enhance completeness and value of IIS data.

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List of Core Data Items

List of Core Data Items
Label Status (Required/Optional)
Patient name: first, middle, last Required
Patient alias name: first, middle, last Optional
Patient address, phone number Optional
Birthing facility Optional
Patient Social Security number (SSN) Optional
Patient birth date Required
Patient sex Required
**Patient race Required
**Patient ethnicity Required
Patient Primary language Optional
**Patient birth order Required
Patient birth registration number Optional
Patient birth State/country Required
Patient Medicaid number Optional
Mother’s name: First, middle, last, maiden Required
Mother’s SSN Optional
Father’s name: first, middle, last Optional
Father’s SSN Optional
Vaccine Type Required
Vaccine Manufacturer Required
Vaccine dose number Optional
Vaccine expiration date Optional
Vaccine injection site Optional
Vaccination date Required
Vaccine lot number Required
Vaccine provider Optional
**Historical vaccination flag indicator Optional
**VFC eligibility Optional
**History of varicella disease indicator Optional
**Patient status indicators that include active, inactive, MOGE, and other classifications Optional

** Changes with the 2007 report.

Other Notes and References:
  • Patient alias name: first, middle, last (former names for management of adoptions and name changes)
  • Patient address, phone number, birthing facility (these variables should be locally defined)

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Immunization Event Identifiers

Vaccine type

(Use HL7-defined Table 0292 – Vaccines Administered (code=CVX) found in Appendix 1. Note that up-to-date versions of this table will be maintained on the CDC Vaccines & Immunizations website.

Vaccine Manufacturer

(Use HL7-defined Table 0227 – Manufacturers of vaccines (code=MVX) found in Appendix 1. Note that up-to-date versions of this table will be maintained on the CDC Vaccines & Immunizations website.

Vaccine dose number

With a fully operating system, this variable is not needed. However, in the real world, and particularly during the initial startup phase, many systems will be gathering partial histories; therefore, to evaluate histories properly, dose number becomes very important.

References for Guidance

Each of the variables listed in the above table are described in detail in the following guides which offer specific guidance on implementation.

The current Health Level 7 Immunization Guide contains both messaging details and coding definitions.

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