It will take "innovative new thinking" and an active, national approach to close the immunity gaps shown by this year's measles epidemic, a leading expert says.
Nearly 2000 measles cases have been confirmed since the start of the year – mostly in the Auckland region and a third requiring hospital care – making it the biggest outbreak since 1997.
In an editorial published today in the New Zealand Medical Journal, Immunisation Advisory Centre director Dr Nikki Turner singled out the the drivers behind it – and where improvements were urgently needed.
In Auckland, case numbers had swelled from two outbreaks that particularly affected children under 2, teenagers and young adults aged under 30.
Māori and Pacific people were also hit hard - respectively making up 39 per cent and 36 per cent of those patients hospitalised.
Vaccination rates were markedly low among those affected: only 6.7 per cent of people admitted to hospital were fully vaccinated, and the figure among patients who didn't need hospital care wasn't much better, at 14 per cent.
Although the World Health Organisation said in 2017 New Zealand had "eliminated" endemic measles, it pointed out at the time there was a risk of future spread because of immunity gaps across the population.
Turner pointed out New Zealand has long had low immunisation coverage in its childhood programme with "significant" equity gaps: in 1991, around a third of Kiwi children hadn't been immunised by the age of 2, although by 2005 that margin had narrowed slightly to about a quarter.
Since then, coverage rates had neared, but never reached the national target of 95 per cent – and there remained equity gaps when it came to ethnicity, socioeconomic status and region.
She saidhistoric low immunisation coverage had left large numbers of young people – Māori and Pacific people especially – either under or unimmunised.
More concerningly, there had been recent drops in coverage, along with inequity gaps, in the infant programme.
"The effects from socioeconomic deprivation have entrenched and increased in some New Zealand communities, creating issues such as crowding and housing instability," she said.
"This affects enrolment, engaged relationships and ease of access to general practice. There can be challenges for working parents in accessing general practices usually only open weekdays."
Similarly, she said, it wasn't easy to close the historic gaps.
A national campaign targeting young people required more support for frontline health services and better access to vaccines – and this group was "notoriously hard" to reach as it was.
On the plus side, she said the epidemic had driven a surge in Healthline calls, and vaccine uptake nearly doubled over August and September, leading to a shortage.
Longer term, Turner said, innovative new thinking would be needed to strengthen the immunisation programme - particularly when it came to targeting high-risk groups – alongside an active, national approach to close the gaps among teens and young adults.
"This year, the New Zealand population has demonstrated a high demand for measles-containing vaccine, an opportunity to build upon."
The Ministry of Health recently received expert advice from a national measles and rubella committee, which it was using to further develop strategies.
This month, the Government announced babies in Auckland aged 6 months and over were eligible receive a free vaccination, and children would all have access to vaccines.
The education and health ministries have also agreed to share schools' overall vaccination rates so they could be included in the National Immunisation Register and used to assist local public health officers.
By the numbers
1928: Confirmed cases of measles in New Zealand since January – including 1554 in Auckland.
152.4 per million: Rates of measles in New Zealand as at September – the second highest in the Western Pacific.
1.5 per cent: Proportion of people on the National Immunisation Register who chose not to vaccinate – up 0.5 per cent since 2017.