Bulk Query of Immunization Information System Data

The Challenge of Immunization Information System (IIS) Query

Immunization information systems (IIS) have been a rich source of data throughout the COVID-19 pandemic vaccination response. The goal of an IIS is to gather information from a multitude of sources throughout a jurisdiction, and merge that information into one complete, consolidated immunization record for each individual. These consolidated records are then made available for numerous IIS authorized users, including individuals who need their vaccine credentials, providers who need their patients’ vaccination status, payers who are working to ensure their members are up to date and public health workers who use this information to refine and direct multiple aspects of their programs, including increasing immunization coverage rates and managing vaccine distribution.

Near real-time query for individual patient records is broadly available across IIS. However, if information is needed on an entire patient group or set of health plan members, this method of single query may be slow and inefficient. Additionally, a significant increase in queries may adversely affect production systems due to volume. The need for data has been exacerbated during the COVID-19 response since many immunizations were given in settings other than the patients’ medical home. In addition, these doses often were not billed for, but rather were funded through the federal government, so claims data is not available for payers.

Queries have increased substantially during the COVID-19 vaccination response. On average, IIS receive twice as many queries as submissions. In one day in one jurisdiction alone, 570,000 submissions were received, dwarfing the approximate number of 17,000 submissions per day for the average IIS pre-COVID-19. In general, it is estimated that IIS are managing roughly a 10x increase in queries during the COVID-19 response. IIS have experienced performance challenges created by the added bandwidth to process increased volume of single query messages.

Potential Paths Toward a Solution - Bulk Query?

In mid-2021, a small representative group of IIS program and technology partner staff met to discuss current innovations and potential solutions in this area. Several jurisdictions have already set up data warehouses, or data lakes, to provide access for bulk queries on cohorts of patients. The American Immunization Registry Association (AIRA, co-convener with HIMSS of the IIP) has also partnered with Les Lenert and the South Carolina Medical Center to pilot test a potential Flat FHIR (i.e., Bulk FHIR) approach to allowing payer and large provider access. Per a recently published article, this approach, while not fully mature, offers promise. Efforts with Health Level 7 (HL7) Fast Healthcare Interoperability Resource (FHIR) standards have produced clinical data repositories based on this standard that can receive HL7 V2 submission messages and respond to population-level queries using the evolving Flat FHIR protocols for bulk transfer of data.

Planned Work, What’s Ahead?

In the fall of 2021, the Immunization Integration Program (IIP) Executive Committee identified bulk query as one of four high-priority topics of focus in 2022. The IIP Collaborative is an active, interdisciplinary group of experts representing organizations across the immunization information ecosystem. Experts from electronic health record systems, health information exchanges, clinical environments, health payers, public health and others come together to generate solutions for challenging interoperability topics. In Spring 2022, a workgroup of nation-wide specialists will be convened to develop a best practice guide that summarizes the innovative approaches across the IIS community for meeting the needs of payers and large providers. This guide will promote a best-of-breed approach to further standardize efficient and secure IIS bulk data access.

This effort will work to leverage other potential and ongoing efforts across the health IT community to address the bulk query need. In particular, the Helios project under the Public Health FHIR Accelerator domain is exploring inclusion of bulk query for immunization data as one of its use cases under consideration. This and other related projects will be included in a landscape analysis to ensure synergy and avoid duplication.

The IIP will be seeking volunteers to adopt the outputs to improve access to immunization data. Stay tuned to the HIMSS IIP webpage for more information as this and other important initiatives move forward.