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Submitting HL7 to PA-SIIS

Providers and clinics interested in submitting HL7 messages to PA-SIIS for patient vaccine information are encouraged to do the following:

Step 1 – Get your organization established in PA-SIIS. To use PA-SIIS, you must register your facility with our Immunization Registry. Complete Request to Create a Clinic in PA-SIIS.  If you are submitting an application to participate in one of Pennsylvania’s Vaccination Programs (including COVID-19), you do not need to complete this form.  Your facility will be assigned a clinic ID as part of the enrollment process.

Step 2 – Begin to use PA-SIIS through the web application. Begin participating in PA-SIIS while you explore the possibility of transmitting vaccination data through HL7.  PA-SIIS provides functionality to enable you to search and report new vaccination data to a patient record.  Get started by completing the PA-SIIS User Account Request form.

If you are receiving vaccine from one of Pennsylvania’s Vaccine Programs (including COVID-19), you must have at least two users enrolled to manage the vaccine inventory that is provided to you through Pennsylvania’s Vaccination Programs.

Step 3 – Become familiar with HL7 standards. HL7 v.2.5.1 Release 1.5 is the standard format for submitting HL7 messages to PA-SIIS.  The following resources will assist you in becoming familiar with our standards.

Step 4 – Utilize PA's customized NIST Tool to self-test the quality of your HL7 messages. Please note that this tool is designed to test VXU messages.  A tool for QBP messages is not yet available.  The NIST tool for PA is available at  See the NIST Tool Instructions on how to use this tool.

The following resources will assist you in becoming familiar with the NIST tool:

Step 5 – Submit a request to transmit vaccination data through HL7. Once you have determined that you’d like to transmit data to PA-SIIS through HL7, complete a Request to Transmit Vaccination Data Through HL7 form.  This form should be submitted between 7-15 days from the date in which you plan to start PA-SIIS testing (as outlined in Step 6 below).  You must send a PDF of the Report from the NIST Tool on your testing results.  See the NIST Tool Instructions for directions on downloading your test results.

Step 6 – Begin Testing your HLT in PA-SIIS UAT. Once you have five or less errors in your HL7 using the NIST tool, begin testing in PA-SIIS UAT using the credentials assigned to your clinic from one of our registry specialists.  Our registry specialist will also provide you with a set of scenarios for you to use for testing purposes. 

Step 7 – Request that a Registry Specialist Review Your HL7 Messaging to Complete UAT Testing. Once you have successfully conducted your independent testing in Step 6, send an email to to request that a registry specialist be assigned to support you through the final round of UAT testing. The registry specialist will coordinate a testing date with you and provide the final set of scenarios to be transmitted on the testing date.   

Step 8 – Promotion to PA-SIIS Production Environment. Once you have successfully completed testing in PA-SIIS’s UAT environment, the registry specialist will verify your clinic ID and provide you with credentials to transmit HL7 messages to PA-SIIS. Refer to the Troubleshooting Connectivity Issues to PA-SIIS – A Guide for HL7 Providers to resolve any connectivity issues.

The registry specialist will meeting with you prior to going live in PA-SIIS to review the self-auditing requirements as listed in the Request to Transmit Vaccination Data Through HL7 form.