Reaching the 90 per cent target could still mean spending about three quarters of next year in the "Red" traffic light setting, but vaccinating children would help, Covid-19 modeller Shaun Hendy says.
Auckland's DHBs are moving steadily closer to reaching 90 per cent double vaccinated, which would trigger a move for the region away from alert levels to the new traffic light system.
That would mean businesses being able to open their doors to customers who could show proof of vaccination, but gathering limits of just 10 people for those choosing not to.
Prof Hendy said operating under the red setting would mean some more freedoms for Auckland, but it would not be a return to "normal life".
"It's gonna take some getting used to. We're not going back to that kind of level 1 life that we've enjoyed for most of 2020 and 2021," he said.
It would also mean accepting there would be Covid-19 circulating in the community for some time yet.
"The traffic light system is designed to be a long-term management strategy, so less about reacting by moving us into lockdown when we have an outbreak and more about managing case numbers," he said, "tolerating some presence in the community without letting it really soak up, you know, all available healthcare capacity."
"We might find ourselves spending, you know, three quarters of next year in the Red, and maybe a quarter in Green or Orange. That's given our current vaccine targets which is 90 per cent of the over-12s."
However, if vaccinations were approved for children aged 5-11, that could make a big difference.
"That might shift us for example to spending 50 per cent of our time in the red traffic light zone, with less impact on schooling."
He did expect case numbers would peak at 200 to 300 cases per day, sometime this month or in December.
While an outbreak on the scale seen in Victoria and NSW with thousands of cases a day was unlikely, case numbers could still get out of control and overwhelm the hospital system, he said.
"There's still the possibility that we could get into maybe as high as 400 to 500 new cases per day. That would put real strain on our healthcare system.
"I think even the coming peak between 200 to 300 cases per day that we think is most likely will put strain on the system. It'll certainly fill up the capacity we have within Auckland to deal with Covid.
"If the outbreak spreads to other parts of the country that have lower vaccination rates within Auckland and perhaps lower healthcare capacity then that could also be quite devastating for those regions."
The Government has already said Auckland will move to alert level 3 step 2 next Tuesday night, and Prof Hendy warned earlier this week that easing of restrictions was too soon and could risk seeing case high numbers persist into next year.
He repeated that concern.
"We'll be relying a lot on the work that retailers can do to ensure that there aren't infections," he said. "It is a bit of an unknown and it will just take a few retailers to not really ... manage that process well to get further spread."
He said case numbers could have dropped already had the Government maintained stricter measures.
"We won't see the full effects of that for a week or two after we shift to that next step. Hopefully, that doesn't lead to an increase in cases or pushing out that date, where we see cases increase. It's got the potential to do that however."
"As we've got more vaccinated they've been relaxing at the same time and so that's why we haven't seen case numbers fall away."
He said while vaccines helped a lot, the reality was they could not prevent the spread of the Delta variant on their own and the next year would be challenging.
"We have been sheltered relative to other parts of the world. We haven't spent as much time in lockdown as say people have in Melbourne and Victoria and we haven't seen the high death rates that they have there and certainly we haven't seen the fatalities that they have in Europe and the United States.
"We're looking at countries that have really tried to go back to normal and they simply haven't. In the UK they're seeing, you know, quite high death rates, very high infection numbers at the moment - maybe 2 per cent of the population currently has Delta.
"In New Zealand that would translate into 20 to 30 deaths per day, which would be serious and significant, so with delta you really can't go back to normal without putting a lot of people at risk and really overwhelming your healthcare system."