By Nicholas Jones in Apia

Measles outbreaks that put New Zealand children in intensive care before likely spreading to Samoa where children died could have been avoided if the Government heeded expert advice and closed immunity gaps fuelled by a racist health system.

That conclusion is outlined in a damning Ministry of Health report, obtained by the Weekend Herald as part of an investigation into how Government inaction left the door open to last year's outbreak of the preventable disease.

It's thought measles spread with travellers to Samoa - a situation that dismays scientists, including Dr Helen Petousis-Harris, an immunologist and vaccine specialist at the University of Auckland.

"Exporting a disease to a country with fragmented health care is something to be ashamed of," she said of that probability, judged highly likely by government officials.

This week, the Weekend Herald visited a Samoan village where at least 10 children died in a catastrophe that savaged the country late last year and claimed 83 lives.

Neighbouring homes in Toamua, just outside Apia, have fresh child-sized burial plots in the front yard. One woman spoke of the loss of two grandchildren, and a pastor who helped bury three children said he'd never lived through anything like it.

"The disease was going from one family to another," Reverend Dr Eletise Suluvale said.

"We are used to one child in a year, or in two or three years. But what we had was seven in one month."

The ministry report was compiled by its communicable disease team with input from the national verification committee for measles and rubella elimination (NVC), a group of the country's top experts. Measles outbreaks hadn't yet taken off in Samoa when the report was finalised in August.

"Outbreaks have been fuelled by the immunity gap in the New Zealand population," the ministry report warned.

"No funding has been available nationally to support supplementary immunisation activities to increase immunity against measles."

Since May 2017, the expert committee made unsuccessful pleas for "catch-up" and targeted vaccination programmes.

"The NVC notes with disappointment that the recent increase in measles importation and subsequent outbreaks could have been avoided had its recommendations been acted upon in a timely manner," the ministry report stated.

Officials were planning targeted immunisation work for 2020, the report noted, but no funding had been committed. Money is finally set to be found; Associate Health Minister Julie Anne Genter has confirmed an imminent announcement. She blamed National for leaving the health system badly underfunded.

However, National's health spokesman Michael Woodhouse said the previous Government boosted immunisation rates for children from 67 per cent in 2007 to about 93 per cent in October 2017, and "since then the immunisation rates of 19 of our 20 DHBs have gone backwards".

Documents show experts on the NVC pressed officials to "address the system factors (including institutional racism) that create equity gaps". Institutional racism is a term that means the procedures or practices of particular organisations result in some groups being advantaged over others.

Dr Nikki Turner chairs the NVC but spoke to the Weekend Herald in her role as director of the national immunisation advisory centre. She said examples of institutional racism could include Māori families feeling less welcome at health services, or being treated differently.

"There are two reasons why we are having coverage problems. The first is the historic immunity gaps particularly in adolescents and young and mid-life adults. The second is lower coverage in our infant immunisation programme, particularly for tamariki Māori and children from low-income families."

Samoan authorities are facing their own criticism. Vaccination rates were among the lowest in the world, and the country's MMR immunisation programme was suspended for months because of the deaths of two toddlers in 2018. It was later confirmed those cases were because of human error when nurses (subsequently jailed for manslaughter) incorrectly prepared vaccines with expired anaesthetic. Fear spread among parents, fanned by anti-vaxxers, and measles immunisation didn't resume until April 2019.

Petousis-Harris said if measles hadn't reached Samoa from New Zealand, it was "a matter of time" before it arrived from elsewhere. Too many unvaccinated people put all countries at risk, including New Zealand.

Turner said both New Zealand and Samoa "learnt a hard lesson last year around where we chose to prioritise our health focus". Her view is if her committee's recommendations had been acted on, then "if not entirely stopping measles, at least there would have been lower rates as the spread would be less".

"While it is really disappointing that New Zealand transmitted measles, currently measles is being extensively transmitted between many countries ... high immunisation coverage is hard to achieve and maintain … [but] measles is preventable."