New Zealand's low rates of MMR coverage mean a new measles outbreak would be far worse than the 2019 epidemic, the Government has been warned.
New Zealand's low rates of MMR coverage mean a new measles outbreak would be far worse than the 2019 epidemic, the Government has been warned.
Newly released briefings show a new measles outbreak in New Zealand would be far worse than the 2019 epidemic, which hospitalised 700 people here and killed 83 in Samoa.
Risks include New Zealand’s low vaccination rate and rising case numbers overseas.
A new measles outbreak in New Zealand would be far worse than the 2019 epidemic, with up to 90 cases a week at its peak and tens of millions in costs to the health system.
Newly released briefings show the Government has been warned another large outbreak of the highlycontagious disease will occur without “urgent and deliberate action”.
While the health system has been trying to plug gaps which contributed to the 2019 outbreak, there are still significant risks – in particular a persistently low childhood immunisation rate.
On Friday, Health New Zealand – Te Whatu Ora said a person with measles on Waiheke Island had completed their isolation period without any further cases being detected. It was the eighth possible measles incursion this year.
“New Zealand remains dangerously close to a measles outbreak, [and] this case should serve as a stark reminder of the very high risk of a measles outbreak in New Zealand,” said medical officer of health Dr Lavina Permual.
In February, Health Minister Dr Shane Reti asked officials for an assurance New Zealand had the “people, policies and parts” in place to prevent and manage a measles outbreak. A series of briefings over the following months have just been released.
An assessment by the Ministry of Health said New Zealand was generally well-prepared to respond to outbreaks of measles but a large or prolonged outbreak would place “considerable” pressure on the health system.
Officials said international measles rates had risen in the last two years, driven by large outbreaks in Malaysia and the Philippines, and the resumption of pre-pandemic levels of international travel increased the risk of incursions.
The measles, mumps and rubella (MMR) immunisation rate in New Zealand was far below the 95% required for herd immunity, officials said, showing just 79% of children between the ages of 1 and 4 had received the vaccine. Despite a catch-up campaign in 2020, rates were also low among 24 to 44-year-olds, who had low levels of immunity to measles.
Immunisation rates were now lower than during the 2019 epidemic, when 2000 people were infected and 700 were hospitalised in New Zealand. The outbreak also spread to Samoa, where 83 people died, mostly children under the age of 5.
“In light of our lower vaccination rates, an epidemic or series of outbreaks may be more severe than that experienced in 2019,” the briefing said.
The cost to the health system would be “significantly more” than the $16 million bill for the 2019 outbreak, a draft Cabinet paper prepared for Reti said. This figure did not include the cost of an emergency vaccination campaign or wider economic costs.
Modelling by the Institute of Environmental Science and Research (ESR) predicted with no increase in vaccinations, a future outbreak would peak at between 80 and 90 cases a week. A worst-case scenario would have an estimated 130 cases a week.
If vaccine rates were lifted by 5% in just one area – Counties Manukau – it would likely reduce the case count by half, the modelling said. Reaching herd immunity would reduce the peak by around 80%.
Minister of Health Dr Shane Reti asked officials for advice earlier this year regarding how ready New Zealand would be in the event of a measles outbreak. Photo / by Michael Craig
Reti was told a sustained epidemic would place pressure on GPs, hospital and specialist services – it was noted primary care in particular was currently suffering from a shortage of doctors and practice nurses. It would also require additional funding for a health system which is currently undergoing a severe budget-cutting exercise.
A Cabinet paper in May identified a series of priorities, including a “wall of immunity” to prevent an outbreak and improving ventilation in schools – one of the most vulnerable environments for airborne transmission.
An external review of New Zealand’s readiness for an outbreak concluded the ministry’s assessment was comprehensive but “overly optimistic in some areas”.
The review by a group of experts said they were “deeply alarmed” by the persistent decline in childhood immunisations and “the failure of current efforts to address this”. They made a series of recommendations relating to governance, surveillance, oversight, immunisation and outbreak planning.
“We encourage the health sector to fully embrace the recommendations in this report. Without deliberate and urgent action, New Zealand will experience a large measles outbreak.”
The ministry and Health NZ said they had accepted all of the recommendations.
University of Auckland vaccinologist Helen Petousis-Harris said it was a relief measles did not take hold on Waiheke Island, which was known for its low vaccination coverage. Photo / Dan Cook, RNZ
University of Auckland vaccinologist Dr Helen Petousis-Harris said there were a number of barriers to preventing an outbreak, especially workforce shortages and a rise in disinformation. Addressing these problems would require a national, multi-faceted response, she said.
Petousis-Harris said it was a relief the disease did not take hold in Waiheke, where vaccine coverage was known to be low.
“It is like chucking a flame into a community that’s essentially dry tinder, as opposed to a drenched rainforest. But I think it’s just a matter of time.”
Isaac Davison is an Auckland-based reporter who covers health issues. He joined the Herald in 2008 and has previously covered the environment, politics and social issues.
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