Eighty-five percent of two-year-olds across the country are now fully vaccinated, the highest number ever.
However the latest immunisation rate figures released by the Ministry of Health show Northland and Bay of Plenty are still well behind the national rate.
Only 72% of infants are immunised in Northland and that rate is falling; in Bay of Plenty the rate is 76%.
The chief executive of Northland's Tihewa Mauriora Charitable Trust, Catherine Turner, says the region's low rate is mostly because of poverty.
The Ministry of Health's chief adviser for child and youth health, Pat Tuohy, says other district health boards have made immunisation a priority and listened to feedback from patients.
Dr Tuohy says Northland is only just starting to do this and he expects a dramatic increase in immunisation there over the next year.
He says only a small number of parents are actively opposed to immunisation and the big issue is making the services readily available.
Dr Tuohy says, for example, if a general practice is only open between 9am and 4pm on weekdays it is impossible for working parents to immunise their children unless they take time off work.
He says the health service needs to more responsive to the needs of the family.