Public health experts have singled out five major areas where New Zealand urgently needs to beef up its defences against Covid-19 - ranging from an alert level overhaul to mandating scanning in cafes, bars and gyms.
In the wake of Sydney's spiralling case numbers, Professor Michael Baker has also recommended New Zealand review its settings around quarantine-free travel with Australia.
His colleague, Otago University epidemiologist Dr Amanda Kvalsvig, told the Herald she'd been often hearing the term "proportionate response" in discussion around our Covid-19 measures.
But with the Delta variant raising the stakes – more than 100 cases have now been confirmed in New South Wales – she said a "proportionate" response in 2021 should mean taking "absolutely no chances" with community transmission.
"Outbreaks increase exponentially so a truly 'proportionate response' to an outbreak risk is always going to seem initially like an over-reaction. It's just a bias that our brains have," she said.
"But this bias is becoming a potentially huge problem now that we have these very infectious variants that can get out of control very quickly."
Kvalsvig and fellow Otago epidemiologists professors Michael Baker and Nick Wilson have listed a raft of urgent fixes they said needed to be made to better protect Kiwis from the virus.
That included an overhaul of New Zealand's alert level system – something they've repeatedly called for in the past.
The researchers said that, while the system may have worked well when it was developed early last year, it was now out of date in several aspects.
A more nuanced system could allow for what they called "nose and mouth lockdowns" – or requirements to wear masks – when stay-at-home orders weren't in place.
Specifically, they said there could be two separate "levels" that enforced mask-wearing – one that applied to people taking transport like flights, buses, trains, taxis and ride-shares, as well as to health facilities and rest homes; and another higher level that extended to all indoor settings, save for homes and primary schools.
The former level could be in place when Australia was seeing outbreaks and the bubble was open, while the latter could apply to a higher-risk situation like Wellington's current one.
"When Wellington was put into alert level after exposure to this infected case from Sydney, people were back at work and mixing with others indoors and hopefully maintaining some physical distance, but there was no requirement to wear masks in most indoor environments," Baker said.
"What we have learned over the last year is that this virus is spread by aerosols – which are not stopped by the 2m rule."
As had been seen in Sydney, he said, it took only fleeting contact indoors to pick up an infection.
"We need to add mass masking indoors to our alert level system, which is widely used across Australia and in many other countries."
The researchers wanted to see the Government make use of the NZ Covid Tracer app, or alternatively paper records, a mandatory requirement in any setting where there was a high risk of "superspreading".
That included cafes, restaurants, bars, nightclubs, gyms, singing groups, and churches.
If used appropriately, the app crucially identified the places visited by an infected person, and that list of locations of interest could be published by officials and used to alert potential contacts, as happened last week.
But the experts said Covid-19 now posed a challenge to contact tracing capacity, because it was now able to spread faster than ever before, and people carrying the virus were frequently asymptomatic while they were most infectious.
While the app was designed to improve both the pace and completeness of contact identification, they said uptake of it to date hadn't been high enough.
Although there were now about 1.4 million devices using Bluetooth tracing – equating to 44 per cent of the adult population – only about 250,000 to 300,000 people were scanning QR codes or completing manual entries each day before the latest flare-up.
Kvalsvig likened the app to a seatbelt in a car: "You hope it will never be needed, but in an emergency, it could make all the difference.
"In the case of the app, it may be the only way to conduct effective contact tracing from a super-spreading event.
"That's why my colleagues and I are calling for mandated use. A mandate sends a clear signal to the New Zealand population about how important this measure is."
The researchers saw a need to lower the threshold for early suspension of travel from a particular Australian state or territory, if there was a risk of community spread in such a jurisdiction.
They said the Government might also need to require earlier and longer adoption of pre-flight testing requirements for travellers from these Australian jurisdictions at times of heightened risk.
Covid-19 Response Minister Chris Hipkins today signalled that could likely become a requirement once the bubble reopened.
Wilson said pre-departure testing could be combined with testing on arrival in New Zealand, once quarantine-free travel with Australia reopened.
"Similarly, an Australian epidemiologist has been arguing for such testing for those moving in and out of the areas under stay-at-home orders in Australia," he said.
"Results of some of these tests, like rapid antigen tests, can be available in 15 minutes and so could have minimal impact on time delays for arriving travellers."
He said saliva tests using PCR could take more time to get results – but should typically allow an infected person to be identified within at least the first day of their time in the community in New Zealand.
"The pros and cons of such different tests and how they are used to protect the transtasman bubble need urgent consideration."
As well, the researchers wanted a review into how mask-wearing could be improved on transtasman flights, and said the Government should seriously consider requiring visitors to use the app over their first two weeks here.
Requiring use of the app for entry into high-risk settings, they argued, would provide a strong incentive for travellers to use it.
Earlier this month, the Herald reported that 3800 border workers were still to be inoculated - and hundreds of workers at the border were not getting tested within the required timeframe.
At that time, around a quarter of Air New Zealand front-line workers still hadn't received both doses of the vaccine.
That was something the researchers wanted immediately remedied.
"Having unvaccinated key workers puts those workers and their families at risk, and beyond those people, all of the rest of us," Kvalsvig said.
"I know that Government is aware of the urgency and I'm hoping that this loophole will be closed very soon."
Kvalsvig and her colleagues pointed out that the original community case in Sydney happened to be an unvaccinated driver who transported international aircrew.
Airline and airport workers had also been implicated in the origins of major outbreaks in Taiwan and Singapore.
Further, they called for stringent occupational health requirements - similar to those in use for other infections in healthcare settings - to require and verify that every person in a border-facing role was vaccinated.
Those who chose not to be vaccinated, they said, should be redeployed away from their current role during the pandemic.
In the event of a community outbreak, they also recommended that existing vaccine stock for the mass roll-out be directed to the region Covid-19 was spreading.
They pointed out that Covid-19 only stopped spreading when people who were infectious were no longer mixing with people who were susceptible.
As a result of the Wellington scare, thousands of contacts were now being asked to stay at home, as was anyone experiencing respiratory symptoms.
The researchers said the Ministry of Health needed to ensure the indications for Covid-19 testing included cold symptoms like a sore throat, running nose, and headache, so they matched with the now well-documented signs of the Delta variant.
If another lockdown was required, they said a high level of support would be needed to support Kiwis' wellbeing – ranging from food security to access to learning and healthcare, with tailored resources for Maori and Māori and Pasifika communities.
Baker said the latest episode in Wellington, and the evolving outbreaks in Australia, ultimately highlighted a need to review the green zone with Australia.
"The Government has suspended travel from all of Australia for three days which provides an opportunity to assess the measures in place to minimise the risk of importing Covid-19 cases," he said.
"The green zone has generally worked well and can hopefully be resumed after this pause and with additional precautions."
Kvalsvig said while the transtasman bubble was important for connecting friends and families, it did raise the risk of outbreaks on both sides.
"It's important to recognise that when the bubble is open we're effectively one population: there's lots of travel to and fro, and visitors are out and about in our major cities as happened last weekend," she said.
"We need to coordinate both information-sharing and alert levels across the Tasman, so that a serious outbreak in one country can trigger additional precautions - and potentially even a step up the alert levels - in the other country."
More than two dozen firefighters battled the fire at its peak.