New Zealand / Covid 19

Covid-19: Experts at odds over move to traffic light system

12:39 pm on 9 November 2021

Aucklanders can expect to move out of lockdown into the Covid-19 Protection Framework - also known as the traffic light system - in just three weeks - but one Covid modeller is warning that strategy is risky.

University of Canterbury's professor Michael Plank says it's risky to ease restrictions in Auckland while cases are still rising quite sharply. Photo: Supplied.

Prime Minister Jacinda Ardern yesterday said there was a "strong expectation from Cabinet" that the city would ease to the red light setting from December, with a decision to be made on 29 November.

However those plans and the decision to further loosen some restrictions in Auckland from 11.59pm tonight are concerning professor Michael Plank from Canterbury University.

"I think it's a risky move to ease restrictions when cases are still rising quite sharply - doubling around every 12 days," he told Morning Report.

Retail stores can reopen in the city tomorrow and Plank said that could see case numbers rise as high as 500 per day around the beginning of December.

If current restrictions remained in place he expected those numbers would peak closer to the 300 mark.

Plank said the government was banking on the fact retail settings were relatively low-risk for the spread of Covid-19 compared with hospitality or large social gatherings but warned any easing of restrictions would inevitably lead to more cases.

"I think [the alert setting changes] will produce an increase in cases, it's difficult to say how much, but it's likely it will be significant."

He was particularly concerned that 700 of the community cases from the past 14 days had yet to be linked.

"We don't know where a significant proportion of these cases are coming from" - University of Canterbury professor Michael Plank

An Australian epidemiologist however, believes now may be the perfect time for Auckland to move to the traffic light system.

Melbourne University professor Tony Blakely said the high number of people in the city with at least one jab should encourage health officials to ease restrictions and take advantage of the community's "peak immunity".

Those who had been vaccinated some time ago would likely begin to see their immunity wane over the coming months, he said.

Blakely's views were based on the experiences New South Wales and Victoria had had while negotiating the lifting of restrictions there.

"Probably Auckland is at peak immunity now and you could come out to play and then as you go up to 90 percent that'll keep the immunity pretty high but there'll be a lot of other people with waning immunity (in the coming months), which we know is a real phenomena."

Citing two recent large case studies in Melbourne and Sydney, Blakely said the "vaccinated economy" - where double-vaccinated people were able to go to pubs, restaurants and events - had worked "better than expected" in the Australian context.

He admitted that could change after Christmas when immunity in both New Zealand and Australia would be expected to start waning.

"I'm not going to tell the New Zealand government exactly what to do I'm just passing on the lessons we've had from over here" - Melbourne University professor Tony Blakely

While he advocated a quick move to the traffic light system for Auckland, Blakely said regional borders still made sense for places which didn't currently have Covid in the community.

"In the South Island of New Zealand, if you don't have Covid in there at the moment, you probably do want to keep that out until you get to at least 90 percent (fully vaccinated) but it's a different story for somewhere like Auckland that already has Covid in it," he said.

Blakely hoped booster doses of the vaccines would help maintain a population's immunity longer term but admitted much was still uncertain in the fight against Covid-19.

"What we don't know is whether those boosters will give you a more enduring immunity into the future; we hope so - but this is all part of the experience that everyone in the world's having of learning to live with this virus and working our way through it."