The Government is being consistent by opting against a snap lockdown for Christchurch - even if more cases emerge in the city, Prime Minister Jacinda Ardern says. 

The decision to remain at alert level 2 was consistent with other responses when there is a strong knowledge of the history of the new Covid community cases. 

The city's current level 2 settings also gave the Government confidence, she said. 

Finding more Covid cases in Christchurch would not necessarily plunge the city back into a level 3 lockdown. 

Instead, tougher restrictions might be applied if new Covid cases were found that couldn't be linked to existing cases. 

The person who tested positive for Covid was returning from Auckland to their home in Christchurch and had a negative Covid test before departing. 

Ardern said that showed the difficulty and complexity of trying to contain the virus' spread. 

She said that it also showed the complexity of vaccine mandates. 

The two new Christchurch Covid cases are unvaccinated. 

However, Ardern said it would not be possible to mandate everyone getting vaccinated before they are allowed to return home. 

When asked if the Government would not enforce a 90 per cent double-jabbed rate in every district health board region, given some were lagging behind, Ardern said the Government wanted to work with those areas to boost their vaccination rates. 

She said the high vaccination targets were set because they will provide the best protection in the event of future outbreaks in each region. 

Ardern said one reason people aren't being allowed to travel from Covid-free Australian states to New Zealand is that it's hard for Kiwi border officials to know where people started their travel from in Australia. 

New Zealand was on a path to opening up to international travel and returning Kiwis and the Government had tried to give everyone notice of the direction its policy is heading, Ardern said. 

However, Covid experts had told the Government it needed to be careful in opening up too quickly. 

The Government's "reconnecting New Zealand" opening of the borders plan remains scheduled for the first quarter of next year. 

MIQ stays to be halved from next month 

Earlier, the Government announced it had decided it will hold Christchurch at alert level 2, Covid-19 Response Minister Chris Hipkins said. 

And he has revealed that MIQ stays will be cut in half from next month. 

The two Christchurch cases have had no major exposure events and all close contacts isolated, Hipkins told reporters at today's 1pm press conference. 

Vaccination rates were above 90 per cent for first doses, and above 70 per cent for second doses in the Bishopdale area, where one of the cases lives. 

Hipkins said the alert level 2 settings continue to keep people safe by limiting gatherings, restricting worksites and encouraging use of masks and scanning. 

It comes as director general of health Ashley Bloomfield revealed 89 new Covid-19 cases in the community today across the country. 

Eighty-three of the cases are in Auckland, four in Waikato and two in Christchurch. 

One further positive result in a MIQ worker was being investigated to see if it was a community or border-related infection. 

Officials this morning have been assessing the level of risk of two cases in Christchurch, one who travelled from Auckland a week ago with a childcare exemption after having tested negative. They had a second negative test before returning to Christchurch on October 15. 

Bloomfield said they returned to Christchurch and became symptomatic on October 18. Their partner got ill a few days later. 

The two cases live together with no other people, and a second household has already been identified as close contacts. 

One of the cases worked for a trucking company and his movements were being checked. He had driven around the Christchurch area, and just north of it. 

All close contacts - across three households - were now isolated. 

There are two community testing centres in Christchurch, which had scaled up to meet the expected demand. 

Christchurch wastewater testing had not picked up Covid-19 - there would be wider testing now done. 

On Auckland, Bloomfield said Bayswater's infection rate had now dropped down. Wiri, Drury, Henderson and Manurewa are now added to suburbs where anyone with symptoms should get tested. 

On the suburbs of interest in Auckland, Bloomfield said in most cases that was because of an infection rate of above one per cent in those suburbs. The highest was Redvale, which had got to 6 or 7 per cent - but that was because it was a small suburb and two or three households were affected. 

There were only three cases in Waikato that had not yet been epidemiologically linked to the outbreak. 

On the Christchurch outbreak, Hipkins said the Government had always been clear there was no way to guarantee that cases would not come up in other regions. 

Asked why vaccinations were not required for those moving out of Auckland, Hipkins said the Government was looking at requiring vaccinations for those travelling out of high-risk areas, especially on flights. 

He said requiring vaccinations for those leaving Auckland had practical problems, and could disrupt supply lines as well as impact on children's care. 

Bloomfield said there had not been cases arising from people such as couriers and drivers crossing the boundary. There was a high level of compliance with the testing regime, and it was working well. 

Bloomfield said it was "not luck" he was relying on. However, transmission was largely from close contact indoors rather than those making deliveries. 

Hipkins said requiring vaccinations for those crossing the regional boundary was "under active consideration" but no decisions had been made yet. 

Hipkins said there was a practical trade-off in introducing a vaccination requirement at the Auckland boundary, because it could slow down supply chains. There was also a question of medical transfers. All of those issues were being worked through. 

Bloomfield said rapid antigen testing was "very much on the table" but if it was to be used as part of the boundary management, it would have to be done and paid for by employers. 

What next for MIQ? 

Hipkins said the MIQ system had worked very effectively, but as vaccination rates lifted internationally only 2-3 cases per 1000 arrivals were being picked up at the border. 

Hipkins said the risk profile had also changed because Covid-19 was in the community. 

He said the government was aware of pressure rebuilding at the border, and the need for room in MIQ for community cases. 

MIQ will be reduced from 14 days to 7 days. 

That will be followed by home isolation for three days. Tests - including rapid antigen and PCR tests - would be used throughout the periods. 

That would free up more rooms for those coming overseas. The new arrangements will apply from November 14. 

The second step of home isolation would begin in early 2022, but only after the traffic light system began. 

The length of time people would be expected to isolate at home would depend on a range of factors, including the risk of the country they came from. 

Hipkins said it was too early to introduce home isolation immediately because Covid-19 was still mainly contained in Auckland. It would risk other cases coming up elsewhere if they were not isolating in Auckland. 

He expected home isolation for fully vaccinated people by the end of the first quarter in 2022. 

Bloomfield said there were 288 positive cases in Auckland which had been cared for at home. 

"We still haven't seen any spread from those cases being looked after in the community." 

Hipkins said a range of issues were considered when deciding whether a positive case could isolate at home, including the size of that person's household and whether there was a low risk of spread. 

On those coming from overseas, Hipkins said the first priority was New Zealanders and those with visas waiting to return before moving to consider other groups such as international students. 

He said tourists were more of a challenge because they did not necessarily have somewhere to isolate. 

Hipkins said the countries listed as high risk were due for another review soon - the last was just before the August outbreak. 

"There could be changes there as a result of the situation we are in now." 

Of the 1500 rooms being freed up, Hipkins said existing bookings would now be re-juggled and an assessment made of how many were needed for positive cases in the community. 

The rest would be freed up for international arrivals. 

On the future of the Australian bubble, Hipkins said one of the problems was that Australia was now opening its internal borders. There was as yet no expectation of re-starting quarantine free travel until it could be done safely and the same rules would apply as from other countries. 

Vax approval extended 

Medsafe has renewed the provisional approval of Pfizer for another two years. Bloomfield said Pfizer had to continue to provide data on its effectiveness and safety as it gathered it. 

The Pages Rd Covid testing centre in Christchurch today. (Photo / George Heard) 

Earlier 

Hipkins said earlier today that the Christchurch cases were not frequent users of the Covid Tracer App, and they had been quite unwell and potentially out and about in the city while infectious for several days. 

Vaccination coverage of eligible people in Christchurch is 89 per cent with a first dose, and 68 per cent with a second dose. That means there are 100,000 people in the city 12 and over who are less than double-dosed. 

Hamilton, Ōtorohanga cases emerge today 

Meanwhile, a third person has tested positive in the small King Country town of Ōtorohanga after two cases at the weekend, linked to an outbreak in neighbouring Te Awamutu. 

A child who has been attending school in Hamilton has also tested positive for Covid. 

Newstead Model Country School was told of the case last night. 

Yesterday the Government extended level 3 in Waikato until the end of Monday at least, but eased some restrictions by allowing outdoor picnics and the return of ECE learning - which also applies in level 3 in Auckland. 

The Delta outbreak in Waikato has seeded in marginalised communities, prompting concerns that it could mirror the outbreak in Auckland and spread all over the North Island. 

Of the 74 cases yesterday, six were in Waikato - all linked - and the rest were in Auckland. 

Epidemiologist Professor Michael Baker said the nature of cases in Waikato was "very concerning". 

"If we can't contain it in Waikato, there's no possibility of a firm boundary around Waikato so it's going to be everywhere in the North Island," he said. 

He wasn't against allowing outdoor picnics in Waikato if it made the restrictions more sustainable, as long as there was a concerted and targeted public health effort on the ground to reach those marginalised groups. 

"That's the huge lesson from Auckland." 

He has called for measures at the boundary around Auckland to be strengthened, but Hipkins said it was too difficult, logistically and operationally, to require all travellers leaving Auckland to be fully vaccinated. 

Hipkins will also announce when shorter MIQ stays will be allowed for overseas returnees. 

This was always going to happen, but the Delta has brought it forward because it has changed the risk profile in Auckland, where almost 300 positive cases are isolating at home. 

In that context, it doesn't make sense to keep fully vaccinated returnees who have tested negative in an MIQ room for 14 days when those rooms can be used for positive cases who are at higher risk of spreading the virus. 

One of the issues Cabinet has had to grapple with is whether to have a different set of rules of where returnees land or live. 

The Government is still chasing zero cases everywhere outside Auckland, which means border controls still need to be tight in cities with MIQ facilities - Wellington, Rotorua, Christchurch, Hamilton - to minimise the chances of the virus leaking into the community. 

Hipkins is also expected to say when MIQ will no longer be needed for most returnees, which will be when the Government has decided there is enough population immunity. 

That will likely be when the 90 per cent vaccination targets have all been met by each DHB, and the country moves away from alert levels and into the traffic light system.