1142: Why Immunization Information Systems Matter

John Sheehan (0:01): This is Public Health Review Morning Edition for Tuesday, 06/09/2026. I'm John Sheehan with news from the Association of State and Territorial Health Officials. Today, Immunization Information Systems, or IISs. Quietly power much of the nation's vaccination infrastructure and help clinicians track patient immunizations, support outbreak response, guide decision making. ASTHO's Senior Director of State Health Policy, Andy Baker White, tells us why IISs are essential to modern public health, how opt in versus opt out policies affect vaccine data completeness, and what lawmakers, providers, and the public should understand as policy debates continue.

Andy Baker White (0:41): Yes. So immunization information systems or a lot of times we shorten it to IISs are registries that are supported by different jurisdictions, both state and local. You know, I think one thing to keep in mind is that these are confidential computerized databases that record all of the immunization doses that are administered by providers to patients who are living in those states and cities and so forth. It's really a backbone for public health, because it it generates information that can be used to support not just clinical decisions between a patient and their provider, but also for public health action when it comes to communicable and infectious disease. You know, vaccines that are administered by these providers are documented, become the data within the IISs, and they can be used to determine when immunizations might be needed.

Andy Baker White (1:46): This information can be used to help remind patients of upcoming vaccinations. And as for public health, you know, it can really be used to guide public health responses to outbreaks, help agencies see where, additional vaccine coverage might be needed, or, you know, what areas might be impacted by an outbreak. So they really, you know, can be there to not just help the individual in protecting themselves by remembering, oh, yeah, I'm I'm due for this next vaccine, but also for the communities at large in in helping to to stop the spread of disease.

John Sheehan (2:27): And you mentioned in a recent health policy update how these systems can really differ across states and different municipalities. How do those variations in systems affect the overall data usefulness or completeness to to the big picture?

Andy Baker White (2:44): Yeah. The different laws and policies that we talked about in the article reflect some of the policies around IISs that that do impact completeness. So one is the level of consent that is that is needed in order for people to participate in the IISs. Whether that is implicit consent, meaning that an individual is automatically participating. Whereas, they may have the option to opt out.

Andy Baker White (3:14): Or whether the system is set up as an opt in or explicit consent process. So if it's an opt in system, then the completeness is probably not gonna be as robust as a system that that's opt out. Where everyone is required to at least start and they might be able to opt out. But you're gonna capture, you know, more people than if it's an opt in. So the more so the more people that you have in the system, the more data, the the better picture that you're gonna have of the the community's vaccine status.

Unknown Speaker (3:46): You know, what the potential impact of an outbreak of a disease outbreak may be on the community. Because you'll have a better idea of who has the vaccines and so forth.

John Sheehan (3:58): Sure. And, you know, you can you can imagine reasons for different different agencies having different, you know, models, whether it's opt in, opt out, mandatory. But from a from a public health big picture perspective, what are the trade offs when you sort of give those options of, you know, having to say, yes, I want that?

Andy Baker White (4:20): Yeah. Like, the opt in systems, you know, you'll you'll have less completeness. And so I think this is just this could, again, like, just impact the readiness, the response, you know, of a public health action, you know, kinda determining, you know, is is more vaccine for this disease needed? Do we need to purchase that? And thinking back, you know, also like just to the the clinical decision making piece of it, the the part between the provider and the individual patient.

Andy Baker White (4:48): You know, it's it's not gonna be something that the provider would be able to, perhaps access and and and know that, oh, I I I should talk to this patient about, you know, the vaccine that they need. So there can also just be that personal individual cost as well.

John Sheehan (5:04): And you pointed out the the benefit to automatic enrollment where you're you're signed up, and that really is that can be critical for for outbreak response.

Andy Baker White (5:15): Yeah. Yeah. It's good to think back to how the ISS came in to be, which, you know, they they really the idea really goes back to a measles outbreak that occurred in the late eighties, early nineties, where several children died. A lot you know, thousands of children were were infected. You know, doctors, you know, they they just didn't have the view on, you know, the the vaccines that the that their patients had received and and whether their patients were protected.

Andy Baker White (5:42): So, you you know, the importance of allowing our physicians, our doctors to know the vaccination status of our our children, of adults, again, the the ability to provide reminders for any sort of needed updates. And, the impact that the that this data, this information can have in responding to an outbreak.

John Sheehan (6:05): Yeah. And on the other side, from there's sort of the patient side of the opt in, opt out data sharing, and then there's the provider side, what providers have their own reporting requirements and data access policies. How can those mandates and policies affect clinicians' ability to make these decisions?

Andy Baker White (6:26): Yeah. So there is a variation among the states, among the jurisdictions, especially when it comes to whether providers are required to report child immunizations or adult immunizations. So more states require child immunizations to be reported by providers than adult immunizations. So for adult populations, especially in states that don't require providers to report on adult vaccines, there can be a missed opportunity there, you know, by their providers to remind them, to advise them about vaccines that, you know, even as adults, we need to have routine vaccines. Also, you know, with the reporting by providers, it's important, you know, that we have policies that are bidirectional.

Andy Baker White (7:14): So it's not just the provider reporting to the system that they've given vaccination to someone, but also that the provider can access that data of that patient. People change their doctors. They move. So being able to have that information also cross state lines is important.

John Sheehan (7:33): Yeah. And, you know, obviously, from from the greater public health perspective, you know, having that data and having that access, you know, again, is super important. But as you just point out, it's not that easy. And there are policies being proposed to try and collect more of that data. But you say that there are, you know, challenges and opportunities there too.

John Sheehan (7:54): Can you elaborate a little more on that?

Andy Baker White (7:56): Yeah. So we did you know, we were looking at the legislation that's being proposed around IISs. And we're we're seeing some proposals that kind of expand the role of IISs. So we wanted to highlight those, and think about, you know, the potential impacts that this expansion could have. So for example, we noted, in New York, there was a bill that would require vaccine exemptions to be reported to the IS system.

Andy Baker White (8:27): So, you know, that could have some value. You know, it could give a better picture of the vaccine coverage, could help identify exemption patterns, and, you know, maybe, you know, help this help public health, you know, understand, like, the reasons why people aren't getting vaccinated or choosing not to be vaccinated.

John Sheehan (8:46): So what should people be watching out for as these policy debates kinda get shaken out in in legislatures?

Andy Baker White (8:55): Again, I think just, you know, looking out for, you know, the reason behind these systems. Remembering back to that measles outbreak from the eighties and nineties, and understanding that these systems are there to to give us the ability to see the larger picture. They allow us to act efficiently, to act timely, to provide patients with the best information they have so they can make decisions for their own health. And really, what they do is they protect those at risk from harm, from the spread of disease. So I think just as the policy debates continue, again, just remembering why we have these and the purpose behind them is important.

John Sheehan (9:37): Andy Baker White is ASTHO's senior director of state health collaboration between public health agencies and health care systems is essential Director to preparing for and responding to emergency health threats. From supply chain disruptions to large scale public health emergencies, coordinated planning helps ensure health care facilities have the resources they need to continue serving their communities. ASTHO sat down with John Lujan, Public Health Emergency Preparedness Program Manager for Guam, to discuss how the jurisdictions Guarding the Pacific Conference helped strengthen health care readiness and support response efforts across the unique challenges of the island jurisdictions. Read the full blog post at the link in the show notes. Laboratory capability is an important aspect of public health emergency preparedness and response.

John Sheehan (10:26): Effective lab testing is critical to successfully detect and understand different public health threats during public health emergencies. On June 29, join ASTHO and APHL for a webinar focused on how health agencies can coordinate with public health laboratories to support emergency response. This webinar will highlight how California coordinated across departments in response to a recent botulism outbreak related to infant formula. Find more information at the link in the show notes. This has been Public Health Review Morning Edition.

John Sheehan (10:57): I'm John Sheehan for the Association of State and Territorial Health Officials.