Northland is lagging behind the rest of the country when it comes to getting kids vaccinated, and health providers are wondering if it's time to make the jabs compulsory.
New figures from the Northland District Health Board show only 90 percent of parents in the region, one of New Zealand's poorest, are getting their kids properly immunised.
Researchers looked at data covering 11,972 children, including most of those born between 2009 and 2013. Of those, 54 percent were Māori, 38 percent NZ European, 2.6 percent Asian, 2.2 percent Pacific and 3 percent other.
But Pākehā kids were much more likely to be denied vaccination by their caregivers, making up 52 percent of all refusals. Māori accounted for 41 percent and Pacific 4.4 percent. Asians and others were most likely to get vaccinated.
Statistics NZ data shows Pākehā in Northland are generally better off financially than their Māori neighbours, so the researchers say Northland's low rate of vaccination can't be blamed on socio-economic factors.
Instead, they suggest Northland's poor record is probably the result of many of its residents "living in a remote area and having difficulty accessing care".
To fix this, the authors suggest it might be time to make vaccination "quasi-mandatory" by making it a requirement of going to school (with "defined exemptions" possible).
They also suggest caregivers who decline the initial six-week vaccinations should continue to be encouraged to bring their kids in for subsequent jabs.
It's recommended at least 95 percent of people are immunised to prevent diseases from spreading, a concept known as herd immunity.
Immunisation rates have improved in recent years, particularly among Māori and Pacific Islanders.