New Zealand needs to act now to make sure it's not left behind when a successful coronavirus vaccine is created, top Kiwi scientists say.

They fear the country could be well down the pecking order to get access to an internationally-developed Covid-19 vaccine, which will be in demand from every country in the world.

Malaghan Institute director Professor Graham Le Gros said there were multiple vaccines being worked on overseas but with unprecedented global demand, manufacturers may not be able to scale up vaccine production to meet it.

"Countries will almost certainly require vaccine manufacturers to meet their own requirements before allowing export to other countries."

Prime Minister Jacinda Ardern has said border restrictions are likely to remain until a vaccine is developed, with estimates that could take 12-18 months.

But Le Gros, the University of Otago's Professor Miguel Quiñones-Mateu and Associate Professor James Ussher are warning the Government not to wait for a Covid-19 vaccine to be developed offshore but instead start contributing here to the vaccine effort.

The trio wants New Zealand to contribute to the vaccine effort, get early access to the vaccine for New Zealand and the Pacific, and at the same time build its ability to respond to pandemics in the future. It should also look at its own vaccine development programme, they say.

"Currently, the vast majority of New Zealand's population is immunologically naive and remains susceptible to Covid-19 for the foreseeable future," Le Gros said.

"A vaccine is the only clear exit strategy that will allow New Zealand to return to normality."

Waiting out the pandemic and relying on sourcing a safe and effective vaccine from the global market in the future is fundamentally the wrong approach, Quiñones-Mateu said.

The group also raised concerns about whether vaccines could be hoarded behind a single supplier and whether countries might close off pharmaceutical exports.

They want New Zealand to start evaluating the best vaccines internationally as well as looking at making our own. The country would also need to build capability to produce enough stock to rapidly immunise everyone in New Zealand once a vaccine is approved - either here or overseas.

The World Health Organisation says there are currently about 70 vaccines in development, with three being trialled in humans.

Le Gros wants the Government to fund a programme that would evaluate international vaccines, develop its own and prepare for rapid production for an approved vaccine.

"The vaccine is not just going to land on our doorstep all nice and shiny and cheap in 18 months' time, unless we get really engaged in our defining partnerships, developing our own programme, developing our own capability, because there's going to be such a global shortage of production capacity," he told RNZ.

A programme would cost tens of millions of dollars in the early stages but that was "chicken feed" compared to the cost of the current lockdown.

"We've got some great technology, great people ready to work ... we're shovel-ready to get stuck in."

New Zealand has the facilities to develop and produce a vaccine if it's protein-based, he said. Scientists would have to modify and change the vaccine, as well as "do deals" if not.

University of Otago Associate Professor James Ussher said the Government couldn't afford to "sit back and hope for a best-case scenario".

It could be reasoned that New Zealand was best to source a vaccine globally given the high cost of vaccine development, clinical trials, and manufacturing, he said.

But the challenge with this strategy was that we do not know when that future will be, what a safe and effective vaccine against Covid-19 should look like, and whether countries might hoard vaccines behind a single supplier, and close key pharmaceutical exports.

The scientists are talking to the Government, academics and industry about a rapid response plan.

-Additional reporting RNZ