And Director-general of health Ashley Bloomfield has warned that Covid cases will continue to rise and that Auckland's border will need to stay in place until the rest of the country's vaccination rates also climb.
Cabinet is to meet today to decide on alert levels for Auckland, Northland and Waikato, which are currently at level 3 while the rest of the country is at level 2.
A total 9039 first jabs were administered across Auckland on Saturday, along with 32,042 second doses, amid the nationwide vaccination push.
A shortfall of 20,360 vaccinations left Auckland "tantalisingly close" to the region reaching the 90 per cent mark for first doses, Bloomfield said.
Auckland's Covid cases, though, "will keep increasing", Bloomfield said.
Even though growth in case numbers dipped over the weekend, Bloomfield said the R value was between 1.2 and 1.3 which means cases will continue to climb. The R value (or reproduction rate) is the number of people which each case passes the virus on to.
Bloomfield told Mike Hosking on Newstalk ZB this morning that he was pleased with 130,000 vaccines going out on Saturday.
It's nearly 1 per cent of the eligible population, however they would continue to vaccinate.
The first jab rates were very high and a bit slower than expected but they were still going up.
As for Melbourne and Sydney opening up at 70 and 80 per cent, Bloomfield said they were in a different position and New Zealand was aiming to have a higher vaccination rate.
Their rates were still coming down and hospitalisation rates weren't going up, however Bloomfield said that was because people were vaccinated.
The best way to stop people ending up in hospital was to get people vaccinated and didn't want hundreds and hundreds of cases.
Asked what mattered if someone tested positive, Bloomfield said it was more likely they would end up in hospital.
Hosking said hospitals in Sydney and Melbourne were not being overwhelmed. However, Bloomfield said they were still under pressure.
Asked about Northland, Bloomfield said they hadn't seen any cases in the next few days which was good but they still weren't clear where they had been.
Bloomfield said Waikato was "interesting" in regards to its moving alert levels especially with cases at the weekend but he had already passed on his advice to Cabinet which would meet to discuss the options this morning.
The 90 per cent was a figure that Bloomfield had given, he said a first jab was a good milestone but he preferred to get people fully vaccinated.
He said they had MyCovid record announced last week that had a QR code that could be used and an international pass and would be available late November.
With the new traffic light system, there was framework happening and that would be announced this afternoon.
Bloomfield told RNZ this morning that current modelling shows it will take Auckland just over a month before 90 per cent of the population is fully vaccinated.
Just over 70 per cent of the region is fully vaccinated now with close to 90 per cent having had one dose.
The Auckland border will need to remain in place until vaccination rates improve in other parts of the country as well, he told RNZ.
Bloomfield told TVNZ's Breakfast programme today he thought New Zealand was still doing "really well" in comparison to other countries, including Australia, but more work needs to be done.
He acknowledged that Super Saturday's event had seen many people who had been on the fence about vaccination finally come out to get their first jab.
Bloomfield said community leaders and community health providers in the Pacific and Māori promoting vaccination had helped hugely in boosting vaccinations in those communities over the weekend.
Put to him the idea of a level 4 circuit-breaker in Auckland, Bloomfield said that was something that had been proposed by a number of people.
"It's something that we've actively considered and importantly, I've asked for advice from my team.
"But also from the public health teams on the ground in Tāmaki Makaurau and that's informed our advice to the Prime Minister. "And Cabinet will be considering that this afternoon."
He said he would not go into any more detail about that particular aspect until Cabinet met and ultimately announced a decision later this afternoon.
Speaking about the large party held on Auckland's North Shore on Saturday night, breaching lockdown restrictions, he said although he was disappointed, it would be more disappointed for Aucklanders who had done the hard yards over the last two months.
He had a message for those people breaking lockdown rules.
"To those who are doing those things ... I think the number of unlinked cases we are seeing means that contact tracers are really under the pump, and can't sustain what they're doing for much longer.
"Ideally, if we'd had that 90 per cent double-dose level for two weeks, and we had the ability to contact trace, we could get to that situation where we don't have to rely on lockdowns."
As at Sunday, Auckland's coverage for full vaccination stood at 1,013,594 people - or 71 per cent of the eligible population.
"It's not going to help and it's not going to help Auckland come down out of the alert level 3 restrictions sooner."
Today's alert level decision
Ministers have a three-pronged decision on their hands when they meet at Cabinet today, with alert level restrictions in Northland, Auckland, and the Waikato set to be reviewed.
Experts say change is unlikely in Auckland and the Waikato, with cases teetering on the edge of dangerous growth rates. Northland, however, appears to have the outbreak contained and could possibly have lockdown restrictions eased, moving to level 2.
All the while, experts have warned daily case counts have been growing on a trajectory where the number of new cases was doubling around every 12 days.
Deputy Prime Minister Grant Robertson has also warned cases will soon hit triple digits, with the number of daily cases expected to double by the end of this month.
The Ministry of Health's public health director Dr Caroline McElnay last week revealed that just 170 to 180 new cases would put pressure on the contact tracing system.
The ministry has already stopped counting subclusters in Auckland because there were so many unlinked cases.
Covid-19 modeller Professor Shaun Hendy said New Zealand otherwise might have been well placed to move into a new stage of its pandemic response, if not for the worsening Delta outbreak.
"If you'd talked to me a few months ago, before this outbreak, I would have said New Zealand would be in a good position, because we could enter this next phase with low case numbers."
But when case numbers were high, he explained, public health systems like test-trace-quarantine couldn't operate well enough, which pushed the load for reducing cases back onto the public.
"The concern at the moment is we are possibly on the cusp of where our contact tracing and other targeted public health interventions will start to fall over."
Currently, the outbreak's effective reproduction number, measuring the average number of other infections that one case created, was estimated to be between 1.2 and 1.3.
"And if it tilts up to 1.4 or 1.5 - which it might, if some of our targeted public health interventions fall over - then we're talking months at level 3, to bring it down to where interventions can start really taking care of things again."
Because of that growing risk, Hendy and other experts have been pushing for a temporary jump back to level 4, which they say could stop the outbreak from growing much bigger, and buy time to get vaccination rates to where they needed to be.
The Government has signalled no appetite for such a move.
