The rapid escalation of Delta cases meant that a home isolation system had to be stood up quickly because this aspect of the Covid response was still only planning stage, MPs have heard. 

Covid-19 Response Minister Chris Hipkins told the Health select committee this morning that the home isolation was working well but was also under pressure. 

There have been three deaths in home isolation recently, raising enough concerns for the Health and Disability Commissioner Morag McDowell to write to Ashley Bloomfield. 

The director-general of health told the committee that officials had met with McDowell, and he and her had exchanged emails, and she was much more reassured about the process now but she would continue to monitor it to ensure people's need were met. 

Bloomfield said the aim was to contact all cases within 24 hours, and he brushed off comments from Health Minister Andrew Little saying the home isolation system was only expecting 120 cases a day - much lower than the current number. 

Bloomfield said that Little's comments were more around the existing response where there was surge capacity to deal with the outbreak, but the expectation was for a short-term surge and then a return to zero cases. 

"We've had to switch that ... there has been rapid work that has had to happen to help support that switch." 

He said there was active planning around how to sustain that surge response, but that had to happen quickly as the Delta outbreak spread around Auckland and case numbers reached 200 a day. 

The way testing, contact tracing, support in the community, and hospital planning now happens has switched to a system where resources are more focused in a "sustained and sustainable". 

"We need to be able to ensure we can do all those things, while the health system can deliver all the other care we need," Bloomfield said. 

"We want to be able to have planned care as well as deal with the outbreak." 

Hipkins was also asked about why cases were isolating in the community when Kiwis overseas returning to Auckland still had to go into MIQ. 

Opening the floodgates to Kiwis overseas would see a "greater cumulative risk", he said. 

"I do understand why people look at that and think, 'gosh, what's the logic here?' There is a logic to it. It does require a bit of working through." 

Hipkins said many more cases could appear all over the country if 20,000 people a week started arriving and heading into home isolation. Currently there were about 50 to 100 cases a week with about 2000 returnees arriving. 

"Even with a rapid antigen test, there's no gaurantee that you'll pick it up at the border ... We will be moving early in the New Year to progressively rolling out home isolation for returnees." 

Their appearance at the committee comes as the Government launches its vaccine certificate today, Waikato wakes to level 2 - prompting concerns about the virus spreading to other regions - and Years 1 to 10 students in Auckland and Waikato return to school. 

The My Covid Record site already crashed this morning because too many people were trying to log on to get their certificates, and Hipkins urged patience and for people to try over the next few days. 

Prime Minister Jacinda Ardern will also reveal a date when Aucklanders will be allowed to leave the city, and for people outside Auckland who want to visit. 

The plan is expected to include vaccination status, and spot checks at the boundary rather than a hard checkpoint where every person in every car is vetted. 

Stronger boundaries are still possible for some regions - such as Northland - to check vaccination status or test results if vaccination rates stay low. 

Auckland is at level 3.2, but will move into the traffic light framework when its three DHBs hit 90 per cent of eligible people fully vaccinated, or soon after Cabinet reviews DHBs' progress on November 29. 

Ardern is also asking public health experts about moving the country into the traffic light system framework before the 90 per cent target is reached across each and every DHB. 

Public health experts warn that this could expose communities that are vulnerable and less vaccinated - especially rural and Māori ones. 

Bloomfield has said that the new framework is safer than level 2 because it allows fewer chances for the virus to spread among unvaccinated people, but it is not safer than level 3 because there would be no household bubbles, and it would be impossible to strictly enforce restrictions on home gatherings. 

The Government is also facing questions over home isolation, and whether enough medical care is available following the deaths of three people, including one that was coughing up blood. 

Home isolation had to be stood up quickly as the number of Delta cases spread across Auckland, but the Government's preparation has been questioned. 

"The system wasn't ready for the rapid escalation in the number of daily cases," Health Minister Andrew Little told Newshub last week. 

"Whereas the system was preparing for 100 to 120 cases a day, we're seeing 150 to 200 cases a day and it just did not expect to be responding to that volume of cases." 

Ardern has also announced that booster shots will open from November 29, with people allowed to have their third jab six months after their second. 

Studies have shown that a booster shot provides even more immunity than there is after dose two, and increases the efficacy against symptomatic infection. 

A record 222 Covid-19 cases were reported yesterday, with 91 people in hospital including seven in ICU or HDU. The ministry also reported a patient in their late 70s at Auckland City Hospital with Covid-19 had died. 

Active cases are now in Auckland, Northland, Waikato, Lakes district, Taranaki, Mid Central, Wairarapa and Canterbury. 

The case numbers took the rolling seven-day daily average to 187, roughly in line with Government modelling.