Significant measles outbreak almost certain to happen, public health expert Michael Baker says

By Rowan Quinn of RNZ

New Zealand will almost certainly have a significant measles outbreak this year, public health experts say.

And there are fears very young children will die.

Measles cases are growing globally, with a 45-fold increase in Europe in the past year and hundreds of cases in Britain since October.

Otago University epidemiology professor Michael Baker said New Zealand was in line for a significant outbreak.

"I think it is almost certain unless we do rapidly raise vaccine coverage, because the problem with measles is that it's so infectious you need very high coverage with not too many gaps in a population if you want to stop outbreaks," he said.

An outbreak could be similar to the one in 2019 where there were more than 2000 cases and hundreds of people hospitalised, many of them under five, he said.

Māori Health Authority/Te Aka Whai Ora clinical director Rawiri McKree Jansen said many people were travelling between New Zealand and countries with active cases.

"Every public health physican, every population health expert I know agrees that it is almost certain we are going to get cases across the border and, given our low immunisation rates, we're at really high risk of having an outbreak," he said.

Hundreds of children were hospitalised in New Zealand in the last outbreak, none died.

But since then, vaccination rates had fallen, he said.

"No expert I know says we're going to get through the next outbreak without seeing some tragic deaths of babies," he said.

About 95 percent of people needed to be immune to achieve herd immunity for measles.

Ministry of Health figures showed just 83 percent of two year olds were up to date with their vaccines - which included measles. For tamariki Māori, the rate was 70 percent.

McKree Jansen said the health system had consistently underperformed when it came to delivering vaccinations to Māori children.

About 95 percent of people needed to be immune to achieve herd immunity for measles.
About 95 percent of people needed to be immune to achieve herd immunity for measles. Photo credit: Newshub

He urged health teams and parents to do everything they could to get them vaccinated.

New Zealand also has an immunity gap among tens of thousands of young adults who missed out on one or both vaccinations when they were children, many because of a problem with the system at the time.

A catch-up campaign had been under way for years to try to reach them.

Baker said the measles vaccine was in many ways a "dream vaccine", because two doses gave most people near-lifetime immunity, and if enough people were reached, it stopped spread through the community.

McKree Jansen said Te Aka Whai Ora was working with Māori health providers to reach as many unvaccinated people as possible.

Te Whatu Ora/Health NZ said it had a national response plan ready to go if an outbreak occurred, including an incident response team, which was mobilised six times last year because of cases which came over the border.

A spokesperson said in the largest incident then, it kept an outbreak contained to six cases.

Baker said it was important New Zealand did all it could to prevent the disease spreading to the wider region, with an outbreak in Samoa that killed 83 people in 2019, which likely spread from New Zealand.