Every Kiwi is set to be offered "incredibly effective" Pfizer jabs after a new sale and purchase agreement was negotiated in the last month.
The Government says securing an additional 8.5 million doses to cover 4.25 million people won't materially impact the timeframe of the largest vaccination programme in New Zealand's history - but it could simplify it.
Making Pfizer the primary provider means streamlining the rollout with efficiencies like only training vaccinators once, ensuring everyone had access to the vaccine with 95 per cent efficiency and medicines regulator Medsafe already giving its approval.
Jacinda Ardern told RNZ 2021 was the year of the vaccine and suggested New Zealand could reach herd immunity for Covid-19 by the end of this year.
Herd immunity is when when enough people have immunity, either from vaccination or a past infection, to stop uncontrolled spread.
Herd immunity doesn't make any one person immune, and outbreaks can still flare up. It means that a virus is no longer easily jumping from person to person, helping to protect those who are still vulnerable to catching it.
"You're right to point out that not everyone will be vaccinated, that is why those who can be are," she said.
Ardern said that the Covid-19 jab had not yet been approved for children and whether it was safe for under-16s was not a decision for her.
Covid-19 Minister Chris Hipkins told the AM Show the scheduled Covid-19 vaccination programme is a first for New Zealand. "The first half of the year is certainly going to be big."
As for how to do it in the time frame, Hipkins said the government is working on that and included making sure there were enough vaccinators as well as having transport companies on board as well as IT and HR support.
"Getting the vaccinators ready is already underway... vaccines will be available in a whole lot of different locations. There will be drive through sites where we can do a lot in one day."
That would happen in the second half of the year, he said.
As for who gets it next, Hipkins said the first quarter's worth of vaccines had arrived but the rest of the framework as to who gets their vaccine would be released by the Government tomorrow.
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The Government would be keeping a record of everyone who was being vaccinated.
It was likely that people would need a Covid-19 vaccine to get around the world as is common with other vaccines, Hipkins said.
If people didn't have the paper work, managed isolation would be an option.
Asked whether they would stop people coming in, Hipkins said they likely couldn't stop residents but for visitors "it had a certain element of inevitability about it".
He confirmed there were no new community cases overnight.
Officials have so far advised that the nine ultra-cold freezers it ordered to hold up to 1.5 million doses might suffice for the extra order if Pfizer is able to spread its deliveries into smaller amounts rather than a few larger orders.
Covid-19 Response Minister Chris Hipkins said there could be pressure on securing the syringes which ensure each Pfizer vial provides six doses rather than five as they're internationally in short supply.
The country has enough of the special LDS syringes for the first part of the vaccination campaign and was seeking to secure arrangements for more later in the year.
Hipkins said there would be additional costs to ensure every Pfizer dose was kept ultra-cold and not spoiled but those would be offset by only having to deal with one vaccine "rather than multiple vaccines with multiple protocols".
He called the Pfizer vaccine "incredibly effective". It was shown to be about 95 per cent effective at preventing symptomatic infection.
The Pfizer vaccine is more expensive than most of its rivals but Prime Minister Jacinda Ardern said it was worth it.
"I think it's fair to say no matter what vaccination you're talking about, it all comes at a much lower price than the price of loss of life or what we've seen with the ongoing hits that many businesses take if we have outbreaks.
"So in our minds this is money very well spent."
It's hoped the other three vaccines on-order could have their deliveries pushed back until next year to become Covid-19 booster shots, and meaning there'll be more to donate and offer to other countries.
The other more easily distributable vaccines could also be offered to Kiwis in rural and hard to reach parts of the countries.
Prime Minister Jacinda Ardern said Realm countries and Pacific nations also might prefer other vaccines which are less complex to distribute without the need for a -70C cold chain.
The next vaccine likely to get Medsafe approval is Janssen Pharmaceutica while New Zealand also has agreements with Novavax and AstraZeneca.
The first round of vaccines for frontline border workers is in its "final stages" and the next group offered jabs will be their households which is estimated to be about 50,000 people.
The Government will reveal which New Zealanders will be in which priority groups - known as the vaccine schedule - on Wednesday.
Ardern said sportspeople and other Kiwis needing to head offshore to represent New Zealand, like the Black Caps and Olympians, might be granted early access.
National's Covid-19 spokesman Chris Bishop criticised the speed of the rollout and said we were fast approaching a situation where sportspeople had to be bumped up the queue so they could compete in major international events.
Bishop accused the Government of being "secretive" about its vaccine plan.
"No one wants to deny our elite sportspeople the chance to compete in these events but it's only fair that every New Zealander knows where they stand in the vaccine queue compared to them."
