Bay health leaders are concerned following a steady decline in immunisation rates in 8-month-old babies.
The Ministry of Health's target rate was 95 per cent but figures from the National Immunisation Register showed Māori rates had dropped to 71 per cent vaccinated while New Zealand European fell to 83.6 per cent from January 1 to March 31 this year.
The low rates were flagged at a Bay of Plenty District Health Board meeting and DHB child and youth and pharmacy portfolio manager Tim Slow said it was "very concerned" about the decline.
He said various factors contributed to the decline, including social resistance to vaccination programmes and barriers preventing parents from completing vaccination visits on time, such as unreliable transport, poverty and work schedules.
He said the decline followed a global trend as a World Health Organization report identified "vaccination hesitancy" among the top 10 threats to global health.
The DHB had taken a number of measures to improve vaccination rates, including creating a vaccine programme performance monitoring committee, improving informational messaging to engage non-vaccinating parents and creating a temporary project leader position to improve Māori engagement, Slow said.
Slow said doctors clinics were arranging vaccination clinics in community settings, such as schools and maraes, to improve access.
Toi Te Ora medical officer of health Phil Shoemack said every opportunity was taken to inform the public on the benefits of immunisation and there was strong public support for immunisation as national rates stood at more than 90 per cent.
He said it was important to note even those who were not fully immunised often have had some vaccinations.
Ngāi Te Rangi's chief executive Paora Stanley said the low Māori vaccination rate was attributable to a range of reasons but poverty played a major role.
He said some people had "bugger all money", which meant paying for health appointments slipped down the priority list when the focus was putting food on the table.
Transport could also be a barrier - getting to appointments could be a challenge if the family had only one car - or no car at all.
Furthermore, he said primary health organisations often failed to reach or effectively engage Māori communities.
"It's easy to blame those vulnerable communities for being vulnerable."
He said it was vital that Māori health workers delivered services to Māori and the best way for services to be delivered was through grassroots community environments that involved the whole whānau, such as community groups or maraes.
Tauranga mum Claire O'Shaughnessy said both of her boys, aged 3 years and 17 months, were fully vaccinated.
She said it was a "no brainer" decision to get them vaccinated after witnessing the impact that preventable illnesses such as whooping cough could have on children.
She said it could be a struggle to fit doctor appointments into working schedules, but she said her husband and herself worked together to ensure their children were fully covered.
"Your kid's health comes before anything else so you just have to make it work," she said.
She said the couple had chosen to get both of their sons' measles vaccinations ahead of schedule.
They also opted to give their boys meningitis jabs, which cost the couple around $1000. She said she could appreciate that solo parents or those on low incomes would not be able to foot such bills.