Vaccines move through more than just your body
It's vaccine season. Not necessarily in an official sense, but with the approach of winter comes the invariable rise in respiratory illness and the shots designed to prevent the worst outcomes. (Quick PSA: go get your flu shot and COVID booster. Both are important, and it would actually make me happy if you stopped reading this to schedule an appointment.)
Vaccines are pretty amazing things; they can prevent infection—though the rate varies and practically no vaccine blocks all infections in everyone—and even when they don’t, they reduce the chances of severe illness, hospitalization, and death. A small amount of substance—sometimes less than a milliliter—added to your body provides a wealth of protection. We have vaccines to thank for the eradication of smallpox and the great reduction in measles and polio worldwide.
Those jabs take more than just a biological journey, however. Healthcare IT has played an important role in vaccine administration and monitoring for years, and we should acknowledge and applaud the success of vaccine-related integrations.
Through vessels and VPNs
A vaccine visit tends to be pretty straightforward. A qualified clinician will identify and prep the correct products, ask about any allergies or previous reactions, and administer the dose. From there, your immune system picks up on the new entrant and begins its response. Special white blood cells called B cells produce antibodies to protect against the antigen, and another kind of white blood cell called T cells "memorize” the pathogen so that they can recognize it in the future and respond more quickly.
While all of this goes on, the clinician has likely documented the vaccine administration in your electronic medical record, which triggers its own call to action. Public health agencies in every state maintain immunization registries to keep track of who has been vaccinated and with which product, and every certified EHR is required to be interoperable with those registries. The EHR compiles information about you and the vaccine you received, such as the lot number and where on the body it was administered, and organizes it into an HL7v2 interface message designed just for vaccines. This VXU message is then sent to the appropriate registries to update them on your new shot.
It isn’t just a one-way street, either. Certified EHRs must also be able to query an immunization registry for a patient’s vaccine history. Imagine that you stepped on a nail and received a tetanus booster at an urgent care center. You’d want your chart at your PCP’s office to include all of your immunizations, so when your PCP logs in, they can trigger a request to download the latest details. A QBP message fires off to the registry, which will verify it can find you in the database, and if successful, an RSP message will venture back with data to review and reconcile into the medical record.
Integration tribulations
These vaccination integrations provide significant value, but they aren’t necessarily simple or perfect. For one, the lack of a centralized immunization registry means numerous connections are needed. Thankfully the CDC has encouraged standards to minimize variation across the states, but these standards rely on older, tried-and-true HL7v2 messaging. We’re still years away from seeing FHIR APIs as the go-to technology for connecting to immunization registries.
Secondly, guarding against duplicate records is a persistent challenge. Since the registries typically cover an entire state, they receive messages from thousands of sources and maintain databases with millions of patients. They must parse through the demographics to determine if a particular message represents a brand-new patient or someone already in the system. Likewise, the vaccine administration details require diligent analysis to ensure nothing erroneous gets through.
The stakes are high. Public health officials rely on the registries to understand regional vaccination coverage and trends in reactions. Providers and patients rely on registries to identify missed vaccines and ensure children get the right shots on the right schedule. Underlying all of this is a system of interoperability that must be efficient and effective—and it is. While those B cells and T cells silently do their biological duty protecting you from harm, the bits and bytes of vaccine integrations are keeping digital systems up-to-date, and that enables everyone to live safer and healthier lives.
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