Immunization Information Systems


​​​​Immunization Info​rmation Systems​

Updated October 2018

What Are IISs, and Why Do We Need Them?

Immunization information systems (IISs), otherwise known as registries, are confidential, population-based, computerized databases that record all immunization doses administered by participating providers to persons residing within a given geopolitical area. They offer an opportunity for confidential, secure, centralized, and immediate access to immunization records for authorized providers.

IISs offer health care professionals an opportunity to provide up-to-date immunization records to patients, parents, school systems, and other health care professionals. IISs can be useful in identifying under-immunized children and monitoring community immunization rates.

How Can You Benefit from Using an IIS in Your Practice?

Use of a fully functional IIS improves patient care, reduces costs, and streamlines practice work flow. An IIS will:

Save money by maximizing staff time and reducing paperwork:

  • Facilitate work flow and help manage administrative costs by tracking inventory, forecasting needed vaccinations, supporting vaccine ordering, and other vaccine related business processes concerns.
  • Eliminate the need for and costs of coordinating point-to-point immunization record transfers between service providers.
  • Help pediatric practices migrate from paper charts to electronic health records by providing the ability to submit data electronically from the EHR to the IIS, and import patient immunization records from the IIS to the electronic chart, eliminating data entry time and improving accuracy.
  • Improve patient immunization rates and practice Healthcare Effectiveness Data and Information Set (HEDIS) scores, which may be tied to Pay for Performance (P4P) programs.
  • Decrease vaccine administration errors using vaccine forecasting algorithms (?).
  • Assist with patient reminders and recall efforts.

Provide better patient care:

  • Decrease missed opportunities to immunize and reduce inappropriate or unnecessary dosing or vaccine duplication.
  • Improve vaccination record completeness using electronic data exchange with the practice EHR.
  • Allow the patient immunization record, a core component of the pediatric medical history, to be truly portable and follow the patient regardless of service location by generating affordable, accurate records for patients, schools, and child care.
  • Identify vulnerable patients during an outbreak of a vaccine-preventable infection.

Note: Direct practices expenses associated with clinical staff time for input of information into an IIS is included in the relative value unit (RVU) published for the Immunization Administration (IA) Current Procedural Terminology (CPT) code on the Medicare Resource-Base Relative Value Scale (RBRVS).

Are There Common Standards for IISs?

Yes. Immunization Information System (IIS) Functional Standards were first issued by the Centers for Disease Control and Prevention (CDC) in 1997 and have been maintained and updated since that time. The most current IIS Functional Standards, v4.0 take effect in 2019.

What Information Is Entered Into an IIS, and How Is It Protected?

Required elements are critical for record exchange purposes, client deduplication, vaccine management, immunization status evaluation, reminder / recall and data analysis or use purposes. They include:

  • the patient's first, middle, and last name
  • date of birth
  • sex
  • race
  • ethnicity
  • birth order
  • birth state/country
  • mother's first, middle, last, and maiden name
  • vaccine type
  • vaccine manufacturer
  • vaccination date
  • vaccine lot number

Optional core data elements are less important for record exchange. Some optional items (eg, address) may be useful only at the local level. Examples of optional core data elements include (but are not limited to):

  • the patient's alias
  • address
  • phone number
  • social security number
  • father's name
  • vaccine provider
  • and VFC program eligibility

State law requires that information in the IIS be kept confidential, though reporting of immunizations to an IIS are exempt from the Health Insurance Portability and Accountability Act of 1996 (HIPAA) Privacy Rule since it is considered a public health activity. IISs must protect the privacy of all users, including children, families, and providers. According to standards set by the CDC, all IISs are required to have a written privacy policy that clearly defines notice of inclusion in the IIS, access to, and use and disclosure of IIS data. For more information, ask the IIS in your area for a copy of their confidentiality policy.

How Do IISs Benefit Patients and Their Families?

The benefits for patients and their families are both practical and potentially lifesaving. An IIS can:

  • Provide the most up-to-date immunization records for schools, child care, and sports teams.
  • Provide families with their child's immunization records for personal safekeeping.
  • Save time and money by ensuring that patients get only those immunizations that are needed.

Where Can I Find Information About My State or Jurisdiction's IIS?

The CDC has contact information on its IIS State/Territory/Registry Staff—Main and Technical Contacts page

IIS Resources


 The Latest on Immunizations