It is "dumb good luck" rather than good management that no-one else has so far tested positive for Covid-19 following the latest community case, a health expert says.
Auckland University Professor of Medicine Des Gorman believes the recent Covid-19 case in the community shows the managed isolation system is not working as it should, and New Zealand is extremely vulnerable as it waits in the queue for a vaccine.
The Ministry of Health has so far said it is highly likely the woman - who had just left managed isolation when she tested positive - caught the virus within the facility as genome sequencing links her case to another person, who was on the same floor.
Prof Gorman told Checkpoint New Zealand's borders should be closed temporarily while things were improved to face the new strains of the virus, which are said to be more transmissible.
Vaccine timeline leaves NZ 'vulnerable' - Prof Gorman
On 2 February, medicines safety watchdog Medsafe will consider whether to approve the Pfizer/Biontech vaccine for use and could make a decision within a day of that meeting.
Prof Gorman said that was good news.
"I think there's a lot of vaccine hesitancy here in New Zealand and elsewhere. So I think reassuring the community that the vaccine has been rigorously approved is a good idea. And it's welcome.
"Given the Pfizer vaccine has been widely used and has now been put into millions of arms, if there was seriously untoward effects we'd have known by now.
"There is some concern that some of the new strains may be less vulnerable to the vaccines, particularly those where the mutation in the new strain involved the protein that it uses to bind to our cells, but as a generalisation it would appear that the vaccine should work."
The big question is exactly when Covid-19 vaccines will reach New Zealand shores, he said.
"Last year, we were reassured we'd be first in the queue. I'm not sure what queue that was.
"The fact we're not going to get the vaccine until the second quarter of the year, the fact that people who aren't health workers or border workers won't be vaccinated until the third and fourth quarter leaves us very vulnerable.
"We've got a very leaky border, we're trying to use hotels as quarantine facilities, we've got a community which doesn't have any immune resistance to this virus. We are peculiarly vulnerable."
Minister in charge of Covid-19 Response Chris Hipkins told Checkpoint the first shipment (of about 226,000 doses) of the Pfizer/BioNTech vaccine was expected by the end of March, and that was broadly on a similar timeline to Australia's.
"Obviously they are working very hard to meet unprecedented international demand for their product, their vaccine, we do have an agreement from them we'll get our shipment within the first quarter, as I indicated it may be several smaller shipments."
Hipkins said he had been clear about not raising people's expectations of getting vaccines earlier.
"We don't have confirmation of an exact delivery schedule from Pfizer yet ... ultimately there are no guarantees about anything here and if you look at those countries that have made pronouncements about what they're going to do and having to adjust their timetables based on what the vaccine companies can actually deliver.
"There's a lot of pressure on vaccines around the world and vaccine manufacturers but I cannot personally promise that because I don't run vaccination companies."
Other vaccine candidates were expected to arrive in the second quarter, he said.
New Zealand was vulnerable because there was almost no Covid-19 here, and the country was relying on border management which was not working as well as it should be, Prof Gorman said.
"We have five times as many people per capita coming back as Australia does. We are peculiarly vulnerable and if we remain unvaccinated we are going to have trouble accessing other countries.
"It's pretty evident that for you and I to travel later this year, next year, we're going to need first of all a vaccine and secondly proof that the vaccine's worked. So I think we're vulnerable from a mobility point of view, but we're also very vulnerable from a community point of view."
'I don't think we can continue to rely on dumb good luck'
Given the amount of international arrivals entering New Zealand's managed isolation and the number of gaps, the country has been lucky to not see a widespread Covid-19 outbreak, he said.
"We've been on the receiving end of a lot of very dumb good luck. All it required was one or two super-spreaders amongst [the breaches] for us to look more like Victoria than we do. And I don't think we can continue to rely on dumb good luck."
Prof Gorman said it was luck again, and not good management, that there was not a bigger outbreak now in Northland - where the woman lives.
"It just means [the new Covid-19 community case] is not a super spreader, it means she doesn't shed a lot of the virus. She had enough contacts and went to enough places between her becoming infectious and her becoming isolated to have caused a major community outbreak, if she had been a super spreader.
"So on the one hand, it's good management that she recorded where she was and good on her. On the other hand, it was dumb good luck that she's not a super-spreader or a super-shedder of virus particles."
In an interview with Checkpoint, Director-General of Health Ashley Bloomfield said the system could never be 100 percent but he has full confidence in it.
Border restrictions: 'We need to have a reset'
On Tuesday, Prime Minister Jacinda Ardern said border restrictions were likely to remain for most of 2021. Prof Gorman told Checkpoint more restrictions should be enforced and New Zealand's border should be closed to certain countries while quarantine protocols were left to deal with the more severe strains of the virus.
"I think we're at the moment very vulnerable, because we are managing people coming from high-risk countries and low-risk countries too similarly.
"We need to have a reset of our border control protocols and that probably requires a pause on people coming from those high-risk countries.
"I know people say, 'New Zealanders have a right to come home, we can't do it'. Well we did it last year - we put a travel ban on China - and we did it without hesitating.
"For example, if you're coming back from the UK then you shouldn't be in the Pullman in the middle of Auckland city."
Such a border closure would only be needed for three or four weeks while quarantine measures were updated, he said.
"I was surprised yesterday to find out that people were now starting to check on ventilation in hotels, I just about fell off my stool. Shouldn't have been done a year ago?
"There are things I've just taken for granted, like border workers being tested. When you find out they aren't you think, goodness gracious me I must be living in a parallel universe.
"Imagine locking people up in a hotel and not checking the ventilation when you're looking at an airborne virus. That just beggars belief.
"We've simply got to reset our border management given that we're now dealing with more infectious strains, and particularly given that we're not going to have widespread access to the vaccine until very late this year.
"Could we have done better over the last year? Yes. Should we have done better? Yes. Is New Zealand the country that you and I would want to live in right now? Absolutely. Are we at risk? Yes, we are. And we need better management if we're to stay in this wonderful situation we're currently in."