How do we connect our EHR system to CT WiZ

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Getting started when data will be reported through an EHR-HL7 system interface

If your immunization data will be automatically transferred from your own electronic health record system to CT WiZ, we will work with your software vendor to establish a secure connection. The connection will use SOAP web services that use the CDC WSDL to send HL7 messages that meet national standards. Follow the five steps below to get started.

Please contact our Help Desk if you have questions. 


Before you start your application, please review the following:

  • CT WiZ Electronic Reporting Onboarding Process Overview
  • Roles and Responsibilities will help determine who will be involved during and after the onboarding process and what they will be doing.
  • HL7 Instructions Document walks you through the entire onboarding process. It describes:
    • The onboarding application
    • Waiting for testing to begin
    • Meetings throughout the process
    • The configuration and connection of your EHR to CT WiZ
    • The testing and validation of HL7 messages
    • Data quality review of HL7 messages
    • Going Live in Production
  • CT WiZ supports these types of interfaces:
    • Uni-directional interfaces send data from your EHR system to CT WiZ immunization information system (IIS). Data exchanged refers to Message Submission (VXU) and Acknowledgment (ACK).
    • Bi-directional interfaces exchange data in two directions, from your EHR system to the CT WiZ IIS and from the CT WiZ IIS to your EHR system. Data exchanged refers to Query (QBP) HL7 message submissions that are sent to an IIS and Response (RSP) HL7 message submissions that are returned by an IIS in response to a querying system.
    • Query and Response (Query-only) interfaces allow your staff to electronically query CT WiZ from your EHR system to retrieve your patients’ immunization records and forecasting. IMPORTANT: This interface is available only for schools nurses.



Providers complete and submit the Application for Electronic Reporting to CT WiZ (HL7/UI) to register for onboarding.



Testing will be based on your system interface:

Uni-directional Exchange: The testing will focus on unsolicited vaccination record update (VXU) messages. When you are ready, actual patient immunization data (from production) will be submitted in real-time from your EHR system to the CT WiZ QA (test) environment to test the interface connection and message data quality. Acknowledgement (ACK) messages will be returned to your EHR system in response. The organization (or their designee) should monitor the ACKs and take action to correct submissions as needed until errors no longer occur.

  • Phase 1: Confirm that CT WiZ can accept a test message from your EHR System.
  • Phase 2: Validate messages from your EHR that required fields are populated with proper codes.
  • Phase 3: Assess data quality of message content to ensure accurate patient data has been sent.

Bi-directional Exchange and Query and Response: Once the interface has been configured, providers actively participate in the testing process to ensure correct results and confirm that clinical records are properly updated.

  • Phase 1: Testing credentials/URL, connectivity test
  • Phase 2: Query and Response configuration and testing preparation
  • Phase 3: Workflow testing

Testing for QBP/RSP is typically composed of the following elements:

  • Query from the provider organization (QBP) to CT WiZ
  • Response (RSP) from CT WiZ to the provider organization
  • Update (VXU) from the provider organization to CT WiZ
  • Acknowledgement (ACK) from CT WiZ to the provider organization

Providers should apply multiple layers of testing:

  • Submit 25-50 records via VXU to query against for a guaranteed response (exact match and forecast)
  • Query using CT WiZ engineered test scenarios (multi-match or too many matches)
  • Query CT WiZ for real patients receiving vaccinations at the clinic (match/no match, VXU update after vaccination)



When the EHR interface goes into CT WiZ Production and your clinic is actively exchanging data with CT WiZ, your clinic (or its designee) must continue to review the ACK messages to ensure ongoing submission and data quality. Any failed submissions or error messages should be corrected and resubmitted to CT WiZ.



When you begin reporting to CT WiZ, provide the Notice to Patients About Reporting to CT WiZ at your clinic to help make sure patients know their immunizations are recorded in CT WiZ.


CT WiZ for Vaccine Providers and Training