The B4 School Check as a Catch-Up Window for Immunisation

The B4 School Check is the final contact point in New Zealand’s Well Child Tamariki Ora programme, and because the nurse who runs it is required to ask about immunisation status, it doubles as one of the last population-wide opportunities to catch a child up before school entry. Nationally, only around 77% of children were fully immunised at 24 months as at the December 2024 quarter, well short of the 95% target set for 2030, which means a meaningful share of four-year-olds turning up for their check still have gaps on the National Immunisation Schedule. This guide sets out what the check actually covers, what the coverage data shows, and a concrete, ordered protocol for using the contact window around it to close those gaps.

Why some children start school without a complete immunisation record

Immunisation coverage in New Zealand does not fall behind for one single reason, and it does not fall behind evenly. Research into general practices with lower coverage rates found that the barriers cluster at both ends of the relationship between family and provider. On the family side, transient households with contact details that go stale, transport constraints such as a single car shared between parents, competing financial and time pressures, and vaccine hesitancy all contribute to missed or delayed doses. On the practice side, inaccurate or outdated patient records make outreach harder, referral pathways to outreach immunisation services are inconsistent between providers, and stretched staff workloads leave less time to build the rapport that makes a hesitant family willing to book. The same research is clear that no single fix closes the gap on its own — practices that improved coverage did so with a combination of reminder systems, relationship-building, and flexible access, not any one intervention in isolation.

These barriers do not affect every population equally. Coverage gaps by ethnicity are widest at 18 months and narrow, but do not close, by five years of age — which is precisely the age window the B4 School Check sits inside.

What the B4 School Check covers

The check is delivered by a Well Child provider in a community, health or education setting, and families are encouraged to book it soon after the child’s fourth birthday so there is time for any follow-up — dental referral, vision correction, or catch-up vaccination — to happen before the child starts school. Because attendance at the check is itself a contact event, it creates a natural moment to review the National Immunisation Schedule against what a child has actually received, independent of whether the family has been engaging with immunisation reminders up to that point.

The coverage data: how large is the gap, and does it close by school age

The starting point for understanding why this matters is simply how far coverage sits from target, and how unevenly it is distributed.

Coverage at eight weeks — the earliest scheduled milestone — sat at 76% nationally as at the end of January 2025, up from 73% a year earlier, so the earliest gaps in a child’s record are already visible from infancy and, without follow-up, tend to compound rather than close on their own. Internationally, New Zealand’s overall childhood vaccination coverage has also been assessed as low relative to comparable countries: a Global Burden of Disease study covering 2010–2023 placed New Zealand’s 2023 coverage as the sixth-lowest among high-income countries, just behind Australia.

What the data also shows is that the ethnic equity gap in coverage is not fixed — it narrows measurably between 18 months and five years of age, which is exactly the stretch of time the B4 School Check falls within.

At 18 months, coverage was 45.5% for Māori tamariki against 73.4% for non-Māori non-Pacific children — a 27.9 percentage-point gap. By 24 months that gap had narrowed to 18 points (65.3% versus 83.3%), and by five years of age it had narrowed further still, to 9.1 points (67.6% versus 76.7%). Measles, mumps and rubella coverage at five years follows a similar pattern of partial catch-up: in 2023, MMR completion at age five stood at 76% for Māori children, 80% for Pacific children, 80% for Asian children and 84% for children in the “Other” ethnicity grouping, each of those figures a modest improvement on the year before. None of this closes the gap entirely, but it shows that the period leading up to school entry is genuinely doing catch-up work across the population — which is exactly the mechanism a well-run B4 School Check process can reinforce rather than leave to chance.

Why the check does not close the gap by itself

The B4 School Check is universal in design but not universal in uptake, and a check a family never attends cannot surface a missed vaccination. The same forces that delay a child’s immunisations in infancy — a changed phone number, a house move, a missed reminder, competing demands on a family’s time — are just as capable of delaying or preventing attendance at the four-year check. That means the check functions as a catch-up opportunity only for the families who reach it, and the families most likely to have immunisation gaps are often the same families at greatest risk of missing the check altogether. Treating the B4 School Check purely as a scheduling event, rather than as the endpoint of an active follow-up process, leaves exactly the population it is best placed to help under-served.

Closing the immunisation gap around the B4 School Check

1. 1
   Reconcile the immunisation record before the invitation goes out

   Before sending a B4 School Check invitation, check the child's record against the National Immunisation Schedule so the nurse already knows, walking in, which doses (if any) are outstanding rather than discovering it mid-appointment.

2. 2
   Confirm contact details at every touchpoint, not just once

   Verify phone number, address and preferred contact method at each contact with the family — enrolment, well child visits, pharmacy or GP contact — since outdated details are one of the most consistently cited reasons outreach fails to reach families who have moved or changed numbers.

3. 3
   Send the invitation with a specific, not generic, immunisation prompt

   If the record shows missed doses, say so explicitly in the invitation or reminder rather than only referencing the general check, so families understand there is a concrete gap to address, not just a routine appointment to keep.

4. 4
   Use more than one reminder channel

   Combine a phone call, a text message and a letter or portal message rather than relying on a single channel, in line with practice evidence that multi-method reminders outperform any one method used alone.

5. 5
   Offer flexible or after-hours slots for families who repeatedly do not attend

   For families who have missed a prior Well Child contact or the check itself, offer a weekend, evening or drop-in option before defaulting to a standard weekday appointment, since transport and work constraints are a recurring reason families disengage.

6. 6
   Action the immunisation referral at the appointment itself

   When the nurse identifies a gap during the check, refer the family directly to a vaccination provider on the spot rather than issuing a general recommendation to follow up independently, and record the referral in the child's file.

7. 7
   Follow up on the referral within a defined window

   Set a short, specific follow-up window (for example, two to three weeks) to confirm the referred vaccination was actually completed, and re-contact the family if it was not, rather than treating the referral itself as the end of the process.

8. 8
   Review non-attenders as a group, not just individually

   Periodically pull a list of children who are due or overdue for the B4 School Check and have incomplete immunisation records, and prioritise proactive outreach to that group specifically, since they carry the highest combined risk of starting school with unaddressed gaps.

None of these steps depends on new clinical capability — they are about making sure the contact happens, the gap is named rather than assumed, and the referral is followed through rather than left to the family to complete unprompted. For any provider running Well Child Tamariki Ora contacts, a general practice team, or a PHO-affiliated service supporting either, the practical opportunity is the same: the B4 School Check window is one of the few remaining moments before school entry where a child’s whole immunisation history can be reviewed in one sitting, and treating it as an active follow-up process rather than a passive appointment is what turns that opportunity into completed doses.

More broadly, closing gaps like this is as much a follow-up and communication problem as a clinical one — the kind of practical contact-and-reminder discipline described above is the same discipline this site’s other guides for health providers focus on. You can find more of them on the home page.