Australia's Immunisation Gap Is a Recall Problem, Not Refusal

Australia’s childhood immunisation coverage has slipped below the 95% target at every milestone, and the newest surveillance data shows the bigger story isn’t refusal — it’s timing. A growing share of fully vaccinated children are getting their doses weeks or months late, which means the gap is sitting in a practice’s own patient list, waiting on a phone call that a stretched reception team hasn’t had time to make.

Where coverage actually sits today

The Australian Immunisation Register (AIR) is the single national dataset every general practice, Aboriginal Community Controlled Health Service and immunisation provider reports into — reporting a vaccine given is mandatory for every health professional in the country. That makes AIR the most reliable measure of how the schedule is actually tracking, and the most recent quarterly figures are not close to where the National Immunisation Program wants them to be.

Cost isn’t the barrier here in the way it can be elsewhere. Every scheduled dose on the National Immunisation Program is provided free, and the consultation itself is routinely bulk billed at a general practice, so a family isn’t weighing up an out-of-pocket fee before bringing a child in for a catch-up dose. That makes the coverage numbers below more telling, not less — if price isn’t the obstacle, the obstacle is somewhere in the mechanics of getting the appointment booked and kept.

None of these numbers are new lows in isolation, but the direction is consistent. According to NCIRS, coverage at 24 months of age fell below 90% in 2024 for the first time since 2016, and it stayed below 90% through 2025. Coverage at 12 months has dropped 4.3 percentage points since 2020. Five-year-olds still clear the bar most reliably, which tells its own story — the gaps opened earlier in a child’s schedule and were never fully closed, rather than appearing suddenly at school age.

The 95% figure isn’t an arbitrary round number either. It’s the threshold generally accepted as the point at which population immunity against highly transmissible diseases such as measles holds, which is why the Department of Health treats it as the target at every milestone rather than an aspiration to work towards eventually. A practice sitting at 91% for one-year-olds isn’t failing badly — it’s a handful of children per cohort short of a target that only works as a threshold, not an average to be close to.

This is a lateness problem before it’s a refusal problem

It’s tempting to read a falling coverage number as a rising number of families opting out. The on-time data says otherwise, and it’s the more useful number for a clinic to act on, because a late dose is a recoverable dose in a way that a firm refusal isn’t.

NCIRS reports that two in five children received their first measles-mumps-rubella dose late in 2025, and one in five received their second diphtheria-tetanus-pertussis dose late. On-time coverage for the first MMR dose was 12.0 percentage points lower in the last quarter of 2025 than in the first quarter of 2020 — a pre-pandemic baseline the schedule has still not recovered to. These are not children whose families have decided against vaccination. They are children whose appointment slipped past the recommended window and was never actively rebooked.

Why the gap survives inside a system built to catch it

AIR was designed to solve exactly this problem, and on paper it should: every dose a child has ever received is recorded against their name, cross-referenced against the National Immunisation Program schedule, the moment a GP reports it. The register can tell you, for any child on your books, precisely which dose is overdue and by how long.

What AIR doesn’t do is act on that information. It’s a reporting system, not a follow-up system — the mandatory obligation runs one way, from provider to register, and nothing in the AIR Rule requires anyone to then contact the family whose child fell behind. Families with a child not up to date can be flagged through Centrelink’s Family Tax Benefit immunisation requirements, but that mechanism runs on its own periodic cycle and speaks to payments, not appointments. It was never built to be a clinic’s recall engine.

So the actual recall work — pulling the list of children overdue by age and dose, working out who to contact and how, making the call, offering a slot, following up again if no one answers — defaults to whichever staff member has a spare hour between a full morning of bookings and the front desk phone. In a practice managing thousands of paediatric patients, that’s not a process; it’s whatever gets done on a quiet Tuesday. Recall lists, when they exist at all, tend to get worked in one direction: a batch of letters or a single round of calls goes out, whoever answers gets booked, and whoever doesn’t answer drops off the list until the next quarterly clean-up. There’s no dose-level targeting in that approach — a family gets the same generic “please book a check-up” message whether their child is missing one dose or four, and a family who misses the first call rarely gets a second, better-timed attempt.

NCIRS’s own 2024 report names the fix in one line, without softening it: “Enhancing catch-up vaccination activities, addressing barriers to vaccination and optimising equity of access should be priorities across all age groups.” Nobody disputes that recommendation. The gap is that almost no general practice or paediatric clinic has the rostered capacity to run it as a standing operation rather than an occasional catch-up drive — recall competes for the same reception hours as answering the phone for same-day bookings, and same-day bookings win every time because they’re the ones a parent is calling about right now.

What a stalled recall list actually costs a practice

The clinical risk of a widening immunisation gap is well documented and outside the scope of what a practice can fix alone — outbreak exposure rises as coverage drifts below the herd-immunity threshold, and that’s a population-level problem, not something one clinic’s booking system controls. But there’s a more immediate, practice-level cost that’s easy to miss: every overdue child on a recall list is also a continuity-of-care problem. A family that has quietly stopped attending for vaccination is often a family that has also drifted away from developmental checks, growth monitoring and the general practice relationship altogether. By the time a receptionist works through a stale recall list, some of those families have moved, changed numbers, or switched providers, and the contact attempt fails before it starts — which is exactly the outdated-details problem every recall system eventually runs into if the list isn’t worked continuously.

There’s also a simpler, more immediate cost: every overdue dose sitting on a list is a bookable appointment that never gets booked. For a practice, that’s foregone consultations, not just an uncomfortable line in a coverage report — the same capacity gap shows up whether you’re counting missed clinical opportunity or missed revenue.

What proactive recall looks like in practice

The fix doesn’t require a new clinical protocol — the schedule and the eligibility rules already exist in the National Immunisation Program and in AIR. What’s missing is the follow-through: the moment-by-moment work of checking who’s overdue and closing the loop with that family before the gap widens further. This is exactly the kind of high-volume, repetitive, time-sensitive outreach an AI voice and WhatsApp agent is built to run continuously, without waiting for a spare hour to open up in the day.

1. 1
   Flag overdue children automatically

   Cross-reference the practice's patient list against the National Immunisation Program schedule by age and dose, not by whether a booking already exists — most overdue children have no upcoming appointment at all.

2. 2
   Reach out the same week the gap appears

   An AI agent places the call, sends the SMS or opens a WhatsApp message as soon as a child crosses into overdue territory, instead of waiting for the next reminder cycle or a quiet moment at reception.

3. 3
   Offer a real slot on the spot

   The message or call carries an actual booking option against the practice's live schedule, so the family can confirm a time immediately rather than being told to call back.

4. 4
   Confirm the appointment closer to the date

   A follow-up confirmation message the day before reduces the chance the newly booked catch-up slot itself becomes a no-show.

5. 5
   Escalate the families who don't respond

   Non-responders are automatically re-contacted through a second channel — voice after SMS, or WhatsApp after a missed call — rather than falling out of the recall list after one unanswered attempt.

None of this replaces clinical judgement. A nurse or GP still decides what’s clinically appropriate for a given child, and the disclaimer at the end of this piece still applies in full. What changes is that the administrative half of catch-up — finding who’s overdue and getting them back on the books — stops depending on whether someone happened to have time that week. Arbol runs that outreach as a standing process across a practice’s whole paediatric list: identifying who is overdue against the schedule, contacting them by phone, SMS or WhatsApp, offering a bookable slot, confirming it closer to the date, and escalating anyone who goes quiet — the same discipline that already lifts Indigenous five-year-old coverage above the national average, applied to every child on a clinic’s books, every week, not just during a periodic catch-up push.

If your practice runs immunisation for Australian families, this is the same operational gap behind how Arbol works for Australian clinics — proactive contact instead of a waiting room that only fills when a parent happens to remember. You can see the fuller model on the Arbol home page.