Immunologist Graham Le Gros says New Zealand should be bringing in AstraZeneca vaccines if the Pfizer vaccine supply is running short, and there should be a drive to get as many people with one vaccination shot as soon as possible.
The Government may have to manage demand for the COVID-19 vaccine after a rush to get the jab following the latest outbreak.
There are now 562 community Delta cases - 547 of them in Auckland, 15 in Wellington.
Since the outbreak, the Government says the vaccination rate has peaked at more 500,000 a week, compared to pre-outbreak weekly targets of about 300,000.
There are 840,000 Pfizer doses in New Zealand currently. Weekly deliveries are coming in, but the next large delivery is not due until October.
"At this point, given the fact that we're so vulnerable, yes I think it's really important we give everyone one jab," of the COVID-19 vaccine, immunologist and chief executive at the Malaghan Institute Prof Le Gros told Checkpoint.
"I think that getting bigger coverage, 50-60 percent of the population having at least one jab, because one good thing about the one jab - it does stop the dying and hospitalisation, which is the thing that we're really afraid of here in New Zealand.
"I would throw the vaccine textbook at this business right now, because you've got to remember we're one of the few countries in the world with no community transmission of the virus; we're completely vulnerable.
"Every other country has various cooking up of different viral variants, and we're quite vulnerable now - we need to get vaccinated relatively quickly now, and put all the good efforts and organisation we have into work getting vaccinated as quick as possible with one shot."
He said the country is in a tough situation, and simply vaccinating where it is easiest to get as many people as possible inoculated should be the strategy.
New Zealand has contracts with AstraZeneca and Janssen, and both those company's vaccines have passed MedSafe approval.
Prof Le Gros said the best secondary COVID-19 vaccine for New Zealand would be AstraZeneca.
"We're really lucky, we can now look at some of these small clinical studies which have been done by calm called Com-CoV, a group out of Oxford and Southampton.
"They've actually tried all the different scenarios, Pfizer then AstraZeneca, AstraZeneca then Pfizer.
"One of the really interesting features about our human immune system, it really makes a very good immune response when you actually have the same thing but change it a little bit. And actually having an AstraZeneca followed by a Pfizer is very good."
He told Checkpoint the Government's strategy has to "jump ahead" of the virus.
"It's constantly evolving and trying to find ways to survive. And we've just got to get our immune system primed up.
"I think it's been good up until now, the strategy. It has been really good, it's protected us, it's been really good at preserving our humanity. But now I think we need to run a bit faster and put some of the resources we have, and focus people's minds about getting vaccinated. It'd be really important to do that now. We're in a race now."
If supplies of the Pfizer vaccine ran too low in the coming months, Prof Le Gros said another vaccine like AstraZeneca should be brought in.
Even though AstraZeneca's vaccine has shown to be not as effective as Pfizer's, Professor Le Gros said it is far better than having people unvaccinated.
"It's only a matter of time before we have two or three more [COVID-19 cases] coming through so let's use everything we can. Throw the whole tool kit at it.
"Borrow some Aussie AstraZeneca, I think there's 10 million doses, get it over here and let's get started if we're short of Pfizer vaccine for the moment."
Prof Le Gros' Malaghan Institute of Medical Research has also been working on a COVID-19 vaccine. But he said as more evidence is showing a booster vaccination may be necessary next year, his institute is working to provide a good booster.
"We're currently presenting plans to the Government, we aim to be clinically trialling this time next year. So we'll actually have some results around safety and … it's actually a good time even immunologically because people will be protected for about a year."
"I think we need to have a strategy. The New Zealand Government needs to have a strategy for getting that idea around what is the next booster shot, and for people here in New Zealand to get used to the idea they'll need a booster next year.
"It's not a big problem and it's not a failure of the Pfizer vaccine. It's actually just the way the virus is, the way the virus is changing and trying to escape from Pfizer.
"We just need to be ready and have some strategies already ahead, waiting for the virus and whatever comes at us. Jump ahead."