Kiwis shouldn't expect straight answers on when the country will open its border anytime soon, experts say, thanks to the appearance of the "formidable" Delta variant and possible "further mutations" of the virus behind COVID-19.
The Government on Wednesday released the advice it received from the Strategic Covid-19 Public Health Advisory Group, ahead of a public forum on Wednesday that will feature group chair Sir David Skegg, Prime Minister Jacinda Ardern, Director-General of Health Ashley Bloomfield and other health and business leaders.
The advice suggests opening the border in phases, starting with quarantine-free travel for vaccinated people only to the Cook Islands and Australia, provided they too have widespread vaccine coverage.
"The most fundamental bit of advice is we should try and maintain our elimination strategy and to try and continue to have a different life to most other countries as we reopen the borders," Sir David told The AM Show on Wednesday.
"But we are advising that we shouldn't reopen the borders until everyone's had a chance to be vaccinated, which we hope will be done by the end of this year. So we're hoping that we can start a phased reopening early next year."
Just because everyone's had a chance to be vaccinated doesn't mean everyone will be. Israel, which had first dibs on the highly effective Pfizer/BioNTech vaccine, took just two months to vaccinate half its population - but since March, has only managed to creep up to 60 percent coverage.
Polls have found somewhere between 10 and 20 percent of Kiwi adults either definitely won't, or are unlikely to, get the vaccine for various reasons - some will be based on genuine health concerns, others likely on misinformation spread by anti-vaccination groups.
Sir David says that will leave us vulnerable.
"I wish it was going to be 100 percent, but we need to be as near as possible as we can to 100 percent. It's clear that even at 90 percent we won't have some magical state of herd immunity where we can stop doing all the other things. It really is important that we all take that opportunity this year."
Shaun Hendy, a professor at the University of Auckland who specialises in disease modelling, says "close to 100 percent" vaccine coverage will be needed to stop Delta outbreaks from spreading through herd immunity, without further interventions such as lockdowns.
"I think if you had asked me this three or four months ago when we were just dealing with Alpha, I think I would have been a lot more confident about the outlook. But Delta really has changed things," he told Newshub.
"At the moment it's looking like maybe close to 100 percent before we can go back to normal."
In June, one of Dr Hendy's colleagues - Canterbury mathematics professor Michael Plank - led a study which looked at what level of coverage would be needed to achieve herd immunity. They came up with a figure of 97 percent. The figure for the Alpha strain of COVID-19 which emerged from China in late 2019 was a more realistic 83 percent.
"No country is going to get up to that 100 percent mark," said Dr Hendy. "We're all going to be dealing with this problem for some time yet. We don't know how the virus is going to change either... if we see new variants that may change the picture."
Sir David said if we end up with less than 80 percent coverage, we're going to have a "real problem".
"We're assuming that we're going to have to reopen, so if people don't get vaccinated New Zealand will face a different kind of future with a lot more COVID and we'll have hospital admissions and deaths. But obviously we can't remain cocooned off from the rest of the world forever."
Living with COVID like we do with the flu simply isn't an option, Sir David says.
"The more we learn about the Delta variant, the more we learn about just what a formidable enemy this virus is. It's a very different virus from the Wuhan virus last year, and that's going to make it more difficult for us to control it.
"One of the reasons we haven't spelt out in exact detail what we think should happen in the course of next year is that we must expect further mutations of the virus. This virus keeps adapting, and obviously we're going to have to modify what we do as we go along."
He said New Zealand has done "better than any other country", and Kiwis "have a life which is very similar to that before the pandemic", compared to people in most other nations.
"If we were all to get infected by COVID, unfortunately we will have a lot of hospital admissions and deaths and our lifestyle will never be the same again... We've got the opportunity I believe to continue to have a life which is very similar to that before the pandemic - but that's a rare thing on the planet today."
"We've largely had a trouble-free 18 months here in New Zealand, compared to many places overseas," said Dr Hendy, "so we've kept our options open. Maybe that means we'll be more risk averse than other parts of the world when it comes to opening up, but I think our strategy has served us well so far."
New Zealand is at about 16.6 percent fully vaccinated, ahead of the world figure of 15.6 percent.