With Auckland in lockdown for the second time this year, should we expect more disruptive alert level jumps? What are the promising signs that things are getting better? And what more should we be doing in the mean time? Jamie Morton reports.
Will there be more lockdowns?
Until our vaccine roll-out is complete, experts say the probability of more outbreaks and lockdowns point much more to yes than no.
"While I'm hopeful that we'll see fewer outbreaks in the year ahead, the risk is still significant and further outbreaks are likely," Otago University epidemiologist Dr Amanda Kvalsvig said.
"The MIQ system has provided good protection overall and has almost certainly saved many lives.
"But, as we're seeing at the moment, it takes only one less-than-straightforward outbreak into the community to cause huge disruption."
Covid-19 modeller Professor Michael Plank said been border incursions had been occurring once every three weeks, on average, since August.
"Most of these, we've managed to contain at the border and keep pretty small. But obviously, we've had one or two that have snuck out into the community."
One new analysis, led by Otago University epidemiologists and counterparts in Australia, found New Zealand currently faces a risk of up to nearly three "border failures" each month.
On average, New Zealand to date has had 15.5 such failures for every 1000 positive cases detected in managed isolation and quarantine (MIQ) - three of which have led to regional lockdowns.
Given the proportion of positive cases for every 1000 arriving travellers was currently 9.1, this suggested New Zealand was threatened with 1.8 failures each month.
But the researchers said the emergence of new variants - such as the UK strain at the centre of the latest cluster - had raised the risk even higher.
Supposing the variant was 50 per cent more infectious, the projected rate of border failures climbed to 2.8 per month - assuming a linear increase in risk.
In short: high numbers of infected travellers, carrying more transmissible variants, pushes up the probability of border failure, and thus the chances of further lockdowns.
It's worth noting that, in the absence of highly-sophisticated and mass-monitoring systems like Taiwan's, lockdowns remain one of the most effective ways to quickly bring community outbreaks under control.
In an unrestricted environment like level 1, and with the UK variant being involved, the "R" value - or the number of new cases per infected person - can be as high as three.
Where the original strain might have infected 160 people after five links in a chain, the new variant could infect 1000 people in the same time - making the job of contact tracers much harder.
Massey University infectious disease modeller Professor Mick Roberts also pointed out New Zealand had spent little time in lockdown, compared with virtually all other developed countries.
"I suppose that we've lost sight of what life is like in the rest of the world. The Netherlands has a 9pm curfew. In the UK, restaurants are shut until April."
What are the positive signs?
The researchers behind the new modelling did point to an off-setting factor of MIQ and border workers being vaccinated - something now underway, with jabs being delivered to some 12,000 people.
"If the vaccine stops those border workers from getting infected and passing the virus on, that will really help secure the border and reduce the risk of these types of outbreaks in the future," Plank said.
Plank's Te Punaha Matatini colleague, Professor Shaun Hendy, said modelling was being undertaken to find out just what impact that first wave of vaccinations would have.
While there was a possible risk that vaccines might mask symptoms but still enable some transmission, he said, the picture currently looked positive.
Vaccinating household contacts of those workers and front-line health workers would also help, before the roll-out moved on to the wider public later in the year.
Kvalsvig said that immunising those border workers alone was "fantastic milestone".
"These workers are often on low wages and working long hours, and they've taken on a substantial risk to protect the New Zealand population," she said.
It's a huge relief to know that they'll be safer now, and when they and their families are protected, the rest of the country is safer too.
"Although it'll be a while before the whole population is vaccinated, protecting this priority group will be a major step forward."
At the same time, there were signs the threat at the border was starting to subside, with fewer positive cases arriving recently.
That could partly be explained by the introduction of pre-departure testing and falling rates of Covid-19 globally - especially in hard-hit countries like the US and the UK, where case numbers have recently halved.
Meanwhile, New Zealand now had in place a well-honed testing and contact tracing system, that was working in top-gear right now.
Even at the time of Auckland's first regional lockdown in Auckland, contact tracing teams were exceeding the gold standard in the time taken find an infected person's contacts - 80 per cent of contacts in 48 hours.
That meant those contacts could get into isolation and get tested, lessening their chance of spreading the disease.
"We've now mostly had a few cases, among a few small outbreaks, because the contact tracers have been able to contain the leaks," Roberts said.
"This approach has also worked, with varying degrees of success, in states in Australia."
Roberts was upbeat the wider vaccine roll-out in New Zealand would make the chances of large local outbreaks much smaller.
"I'd like to think that, probably toward the end of the year, I'll be able to go to Australia, but with two weeks quarantine in either direction."
What can we do in the meantime?
Epidemiologist Professor Nick Wilson and his Otago University colleagues have set out a raft of improvements - some straight-forward, others not - that could see New Zealand through to the end of the pandemic.
They've suggested an overhaul and expansion of the alert level system, enabling a more nuanced approach to outbreaks, with clearer and more defined rules, but Covid-19 Response Minister Chris Hipkins has signalled no appetite for a shake-up.
At the border, Wilson said tougher measures could include moving all MIQ facilities to military bases outside of cities.
The Government could turn "down the tap" on the volume of travellers arriving into the country - especially from mass-infected "red zone" countries - and eliminate shared areas within them.
It could prosecute those who breached MIQ rules, regularly report any such cases, and even bring in a post-MIQ requirement of home quarantining for five to seven days.
"The great news is the vaccine is looking good, but the not-so-good-news is that the Government is just not putting enough attention into tightening the border," he said.
"People in MIQ are still being bussed to exercise areas - and even with masks, it's very high risk.
"We haven't adopted what Australia is doing throughout all its states and territories, which is people staying entirely in their rooms, throughout their 14-day quarantine."
Wilson was worried that complacency on the Government's part could lead to more border failures and more lockdowns.
"As we've seen again with this current one, they can be messy, expensive, and obviously very stressful for everyone."
Kvalsvig was hearted that several useful changes were starting to kick in now.
"An increasing number of inbound travellers will be vaccinated, and we should also see further reductions in MIQ cases from pre-flight testing and improved testing and infection control in MIQ," she said.
"Daily saliva testing in MIQ looks to be an excellent strategy to identify any remaining infectious people as early as possible.
"However, we're also likely to see more of these highly infectious variants that could tip the balance the other way, so the response will need to evolve and keep on evolving."
As for what each of us could do, Plank said continuing to scan QR codes was incredibly helpful for contact tracing efforts.
"But the biggest thing is getting tested if you develop symptoms," he said.
"It enables us to pick up outbreaks early, and means we're much less likely to have to use an alert level response."