The Health Minister says it's a matter of "when, not if" New Zealand has a measles outbreak as childhood immunisation rates continue to fall.

"We're now at least 10% below our MMR rates to where we were in 2019 — how do you think that's going to go for us? Not so good," Dr Shane Reti said.

Currently around 76% of eligible 2-year-olds are fully immunised, down from more than 80% last year.

The Government's target is to get that to 90% by 2030, investing $1 million to train the Plunket workforce as vaccinators and establish immunisation services at up to 27 sites across the country, focusing on areas where vaccine coverage is low.

The first will be set up in Whangārei at the end of this year.

"This makes sense, as many as 80% of infants and young babies make contact with Plunket in the first 12 months of life", the minister said.

But Dr Nikki Turner from the Immunisation Advisory Centre said more needs be done to turn around falling childhood immunisation rates.

"Just broadening the workforce is not going to fix our problems," she said. "It's harder for families to access their doctors, some people don't even have family doctors, it's harder for people to find someone they trust to talk to and feel confident.

"And of course, social media concerns, you know, misinformation from Covid."

However, the minister said improving immunisation access was crucial.

"I fundamentally believe that people mostly do want to keep their children safe and mostly do want to vaccinate their children so, with busy lives, how can we provide opportunities?" Reti said.

"Be it in clinic, be it in pop-ups, be it in events, how can we go to them if they're struggling to come to us?"