New Zealand was ill-prepared for the Covid-19 pandemic and was caught with its pants down, leading academic Professor Des Gorman has told the Epidemic Response Committee.
New Zealand should have closed its borders in mid-February, not the end of March but it didn't have the resources to do so.
"We went into this pandemic profoundly under-prepared and when we should have closed the borders hard, we couldn't."
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Being properly resourced meant being able to call on the army and police to set up motels, and even a tented village.
"I think we were spectacularly complacent," he said. "Our casualness, born out of 'that's a problem over there' has left us figuratively with our pants down."
Borders were closed to all non-residents on March 19. Anyone with symptoms of Covid-19 was quarantined and the others were required to go into self-isolation under high trust rules until April 10 when self-isolation rules were tightened and strictly managed.
Gorman said returning New Zealanders should have been treated in a "low trust" environment, including having someone checked on the moment they turned off their phone.
"Public health measures have failed all around the world because they keep assuming that humans behave consistently rationally.
"People don't make rational decisions.
"We squandered our major advantage, which was geography," said Gorman, a former dean of the Auckland University Medical School who is advising the committee formed to monitor the country's response to the pandemic.
"The hard work we need to do to stamp it out is because we had failed to keep it out."
Public health units were under-resourced and there was a shortage of personal protective equipment for health workers.
He said Australia had 10 intensive care unit beds per 100,000 people, Germany had 33, but New Zealand had only three.
Prime Minister Jacinda Ardern rejected Gorman's allegations.
"New Zealand, 20 days after our first case, closed our borders to foreign travellers," she said.
"Now, that made us amongst the first in the world to have done that. So I think that was a significant move by us, and we did it very, very early on in our Covid journey."
But she said it was "very difficult for the world to have actually been well prepared for what has become a one-in-100-year global pandemic".
Director general of health Dr Ashley Bloomfield also challenged the suggestion New Zealand was not properly prepared.
"I think for an under-prepared or ill-prepared country, we've done remarkably well, and I don't think we were ill-prepared," he said.
"I think the evidence is in the position we find ourselves now."
He reported two new cases of Covid-19 yesterday, the second day of alert level 3, taking the total of confirmed and probably cases to 1474. Of them, 83 per cent are considered "recovered" cases.
There have been 19 deaths, though no new ones reported yesterday.
There remain 16 significant clusters and Bloomfield said the cluster based around Marist school (94 with 85 recovered) would be the subject of closer study to look at patterns of transmission.
Ardern said New Zealand currently has 3241 people in quarantine or managed isolation, and 25 people had tested positive while being in managed facilities.
Of yesterday's two new cases, one was in quarantine.
Meanwhile Deputy Prime Minister and Foreign Minister Winston Peters made a splash at his first press conference since returning from lockdown in Northland by revealing the Ministry of Health had actually wanted to shut down the border completely, including to returning Kiwis.
He and Ardern made it clear that it had not been contemplated as a serious policy option but it had been prepared for a meeting on March 25.
Peters was attempting to dispel criticism "that the Government's response has been too myopic and captured by advice from the Ministry of Health".
"Both critiques could not be further from the truth."
New Zealand implemented a lockdown before a single person had died from Covid-19; it required self-isolation by international arrivals 17 days after the first case was confirmed; it closed its borders to foreign nationals 20 days after the first case; and it imposed a lockdown 26 days after the first case.
On Tuesday the country moved to alert level 3, which allows takeaway outlets to open under strict controls, including physical distancing.
Ardern said images of crowding outside an Auckland outlet were concerning and officials had been in touch with the company.
Bloomfield said there was power under the new order issued for alert Level 3 to shut down non-compliant premises.
"However, I think yesterday would be a good example of everybody settling into a new regime, and for the most part that worked well, but just ironing out some small matters that do need to be ironed out quickly. "