Low vax rates mean

New Zealand’s ‘‘woefully low’’ childhood vaccine rates mean outbreaks of potentially deadly diseases are ‘‘inevitable’’, experts say.

Northland emergency doctor Dr Gary Payinda said it was not a case of if, but when, Aotearoa saw a measles or whooping cough surge, as vaccine uptake stagnated: ‘‘We are just waiting for an outbreak.’’

In the three months to March 31, 68.3% of 18-month-olds had completed their immunisations. At 24 months, this was 84.7%.

For a disease like polio, recently detected in United Kingdom wastewater, herd immunity is achieved when 80-85% of the population has been vaccinated. For measles, up to 95% of people need to be vaccinated for herd immunity.

‘‘If we need 95% to protect against [measles] outbreaks ... that’s dangerously low,’’ Payinda said.

Vaccination coverage among Māori aged 18 months has dropped to 46.1% nationally. That dipped to 34% in Counties Manukau and Northland.

For children of all ethnicities aged 18 months, Northland’s rate was 47%.

Payinda pointed to Bangladesh – ‘‘one of the poorest countries on Earth, subjected to yearly devastating floods and food insecurity’’ – with a childhood vaccination rate of 84%.

‘‘If Bangladesh can vaccinate 84% and Northland 40%, something is very, very wrong.’’

The next outbreak was almost entirely predictable, he said, and would rip through areas such as Northland and south Auckland.

In 2019-20, New Zealand experienced its worst measles epidemic in decades, with more than 2100 cases

The disease was ‘‘devastating’’, Payinda said: one in