The government has secured another two vaccines, enough for every New Zealander and its Pacific partners, Prime Minister Jacinda Ardern says.

The additional vaccines being pre-purchased are from pharmaceutical companies AstraZeneca and Novavax.

A total of 7.6 million doses will come from AstraZeneca - enough for 3.8 million people, and 10.72 million doses from Novavax - enough for 5.36 million people. Both vaccines require two doses to be administered.

The government already has to pre-purchase agreements for 750,000 courses from Pfizer/BioNTech and 5 million from Janssen.

The cost of the new pre-purchase agreements was not disclosed, but the vaccines will be free to New Zealanders, the government said.

Ardern said the new agreements means the government will now have three different types of vaccine technology available to it in case some are found to be unsuccessful.

She said if the vaccines are proven to be safe and effective by Medsafe, then the government's first priority will be to vaccinate border workers, essential staff and their household contacts.

"We expect vaccines to be delivered to our front line workers in the second quarter of 2021," she said.

"Our aim is to then commence vaccination of the general public in the second half of the year. All vaccine roll out will be dependent on Medsafe sign off and speed of manufacture."

Minister of Health Andrew Little said Medsafe has made changes to its vaccine approval processes to make it faster.

He said Medsafe has agreed to allow pharmaceutical companies to make rolling applications for their Covid-19 vaccines, which means they may submit their data as it is completed and ready for assessment to speed up the process.

"Pfizer and BioNTech and Janssen have already started to submit data, and timing around Medsafe's approval process depends on many factors, such as the data that companies provide and whether it meets internationally agreed criteria for safety and efficacy.

"Medsafe has streamlined its assessment processes and is prioritising the assessment of Covid-19 vaccines over other pharmaceuticals to obtain a vaccine more quickly, but there will be no compromise on the safety of the vaccine. Medsafe will remain in close contact with its Australian counterpart throughout," Little said.

Covid-19 Response Minister Chris Hipkins said work is underway to make sure the rollout is successful.

"New Zealand has never before attempted an immunisation programme of this scale and complexity," he said.

"Workforce planning to ensure we have enough vaccinators is well advanced. There are around 12,000 health professionals already able to administer vaccines and more will be trained.

"And, as part of the new National Immunisation Solution, the Ministry of Health will have an inventory management system for Covid-19 vaccines with accurate information about where they are located and the temperature in central storage facilities.

"This will enable us to track and trace Covid-19 vaccines and consumables, including their expiry dates, to reduce wastage."

The government has also purchased nine freezers that can store more than 1.5 million doses of the Pfizer-BioNTech vaccine. They are due to arrive in the country by the end of the month, he said.

Hipkins reiterated that the immunisation programme does not mean the border will open immediately.

"Our border remains the first line of defence against Covid-19 from imported cases. To make any decisions around borders we need to be confident that the New Zealand population is sufficiently protected.

"It means we will need information on whether the Covid-19 vaccines are effective at providing individuals with protection from contracting the virus and reducing transmission - and a gradual building towards population immunity, which will take time."

Government to provide $75m in support for Pacific partners

Foreign Affairs Minister Nanaia Mahuta announced that the government is preparing to support its Pacific partners to access Covid-19 vaccines.

Mahuta confirmed $75 million of Official Development Assistance had been earmarked to support Pacific and global vaccine access and roll-out.

"New Zealand is pursuing a portfolio of potential Covid-19 vaccines to ensure we have flexibility and choice in the fast-moving global marketplace. We want to make sure Pacific countries can also access suitable options, and have the support they need to run successful immunisation campaigns."

She said New Zealand's approach will be to purchase sufficient vaccines to cover the Realm of New Zealand (Tokelau, Niue, Cook Islands) and its Polynesian neighbours Samoa, Tonga and Tuvalu should their governments wish to take these up.

Included in the $75m support package, New Zealand plans to make a further $10m contribution to the COVAX Facility Advance Market Commitment, which is the key multilateral mechanism that has emerged to support equitable global access. New Zealand is also ready to contribute to wider Pacific regional initiatives as they take shape.