COVID-19 modelling shows 120 deaths and 1700 hospitalisations could be prevented if Auckland was put into an alert level 4 'circuit-breaker' lockdown.
Te Pūnaha Matatini, a Centre of Research Excellence hosted by the University of Auckland, released the new modelling on Wednesday, which explores potential outcomes for Auckland's COVID-19 Delta outbreak.
With no circuit-breaker lockdown, the modelling predicted around 2300 hospitalisations and 160 deaths between October 6 and January 8.
But with a two-week alert level 4 lockdown starting from November 3, the modelling predicted around 600 hospitalisations and 40 deaths, preventing 120 deaths and 1700 hospitalisations.
The researchers noted that while the "likelihood of being able to eliminate the outbreak completely is negligible, there are major benefits to delaying transmission while the vaccine rollout is still in progress".
Prime Minister Jacinda Ardern ruled out a circuit-breaker level 4 for Auckland last week despite calls for one from several experts. Instead, the Government kept the city under alert level 3 for at least another two weeks.
"A number of respected scientists and epidemiologists have suggested a return to level 4 for a defined two-week lockdown to act as a circuit-breaker and limit the number of cases while our vaccinations take hold and strengthen our immunity," Ardern said at the time.
"However, the public health advice, including from teams on the ground and from Dr Ashley Bloomfield, is that two more weeks at level 4 is unlikely at this stage to reduce the number of cases significantly because of the nature of the outbreak and the fact that compliance has been an issue.
"We considered both sets of advice carefully. Cabinet has to take into account a range of factors, including the overall wellbeing of Aucklanders and how hard this period has been. But the consideration that stood out for us the most was the view amongst those closest to the outbreak that this increase in restrictions would not necessarily reduce cases significantly more than the level 3 restrictions we already have."
Under Auckland's current alert level 3, step 1 settings, two household bubbles of up to 10 people are allowed to meet outdoors, and some outdoor recreational activities are permitted.
COVID-19 Response Minister Chris Hipkins, responding to Te Pūnaha Matatini's modelling on Wednesday, said it didn't consider compliance.
"A lot of the modelling unfortunately relies on the assumption that we would get the same degree of compliance with level 4 restrictions after months as we got at the beginning of imposing level 4 restrictions, and we know that's simply not true," he told reporters.
"If you look across the Tasman to our mates across the ditch, they didn't lower their alert level restrictions at all and they still got an explosion of cases after about 60 days of restrictions.
"We have to bear in mind that it's a theoretical model based on a high degree of compliance with alert level 4, which we already weren't seeing by the time we made the decision to step down."
However, Te Pūnaha Matatini researchers note that it was based on "a lockdown that is reasonably effective in reducing contacts between people, but not as good as the peak estimated effectiveness of alert level 4 previously".
Hipkins denied the Government gambled with 120 lives.
"No, not at all, because actually, I think stepping down restrictions and keeping people with you and keeping people willing to follow restrictions is a better bet than keeping restrictions so high that people won't follow them anymore and you end up with a potentially worse outcome.
"I think if you look across Auckland it was clear that we were starting to see compliance with those rules fraying around the edges.
"Now, it doesn't require a big number of people to stop following the rules for there to be quite a significant change in the level of risk."
The Government on Friday announced its new COVID Protection Framework, or 'traffic light' system, to replace the alert levels. It comes into force once 90 percent of the eligible population is vaccinated.
Since Auckland has been in lockdown for months and is close to reaching the target, it could enter the traffic light framework sooner.
Once the traffic light framework comes into force, vaccination certificates will play a major role in determining what freedoms people have. For example, when Auckland enters the Red light, hospitality venues will be able to open with up to 100 people who are fully vaccinated, but for businesses that choose not to use vaccine certificates, only contactless hospitality will be allowed.
Based on vaccination data and bookings for Auckland, Te Pūnaha Matatini estimated that vaccination could reduce transmission of COVID-19 by approximately 67 percent relative to an unvaccinated population, by early January 2022.
