A leading professor says if the Government is intent on going to alert level 3, children should not be allowed back at school.
And if the country is sincere in its bid to eliminate Covid-19, Rod Jackson, a professor of epidemiology at the University of Auckland, says everybody must still adhere to physical distancing rules and keep at least 2m away from other people.
Prime Minister Jacinda Ardern will this afternoon announce whether the country will drop to alert level 3. That will see many businesses able to re-open - albeit with strict physical distancing rules - and an estimated 500,000 people able to go back to work in some form.
He also threw a warning at the Government - if the country does go down an alert level it must also be prepared for case numbers to rise.
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He instead wanted an alert level 3.5 - where businesses can reopen as long as they can keep their physical distance but schools to stay closed.
"My biggest worry about moving to level 3 and I favour 3.5 - that means no kids at school. It means that if you're a gardener and you can go and do your job safely and will be 2m from anyone, if you're a builder and there's only two other builders on the building site.
"Or if you run a takeaway business and you're able to maintain a kitchen with proper distancing because my understanding is that no one has found any cases transmitted by food. Until we think we've eliminated it we need to maintain physical distancing."
He said there were more cases out there and those people were asymptomatic.
Trying to find them would be like "finding a needle in a haystack" so now that case numbers had slowly decreased, that effort needed to be put into random community testing.
"We have got to have missed some cases and it takes one person to cause an epidemic, doesn't it? I think that's key.
"Whatever we do under level 3, which is why I call it level 3.5, [should] mean schools can't open.
"Our biggest cluster is Marist. The idea of being able to keep kids 2m apart is nonsensical in my mind. Is it possible? I've got grandkids, there's no way."
Even only 1 out of 2 cases was being missed, that would mean that in addition to the 582 confirmed active cases today - total minus recovered cases - there would be at least another 582 currently undetected but infectious cases in New Zealand.
"Some active cases may no longer be infectious, so maybe there are 500 undetected but infectious cases."
What random community testing that had been carried out so far was yet to yield any positive results which meant there were likely fewer than one in a 1000 cases, he said.
Testing should increase to its maximum of 4000 per day. If they got to 10,000 and still no cases, then they would know his estimate was an overestimate.
"With fewer and fewer cases out there, we need to go find them. To find every one of those cases we're going to have to test everyone which is going to be like searching for a needle in a haystack but, if we test 10,000 and find none, that means my estimate is an overestimate and that's really important to know."
Jackson stood by the Government's call to close the border, use the alert level system and the level of testing when it did.
"Up until very recently we needed to put all of our tests into finding cases and finding contacts. People have been talking about doing random samples for a while now, weeks, and I've said to them, 'No, no'. All of our effort should go into case finding and contact tracing.
"But we're now down to the point that it's feasible that we can really ramp up the testing. Most of the cases are in the 20 to 30 age group and that's who we should be targeting."
He wanted New Zealand to continue its mission to stamp out coronavirus.
"We're going for something that no one else - maybe Australia, possibly and Taiwan - is likely to achieve, elimination. "
Jackson said he had heard of people declaring these as "unprecedented times". "I think that's an understatement."