New Covid-19 modelling shows that New Zealand will still need lockdowns to control the virus even if 80 percent of those over the age of five were vaccinated.
Even with an 80 percent vaccination rate, the modelling says there would be 7000 deaths and 60,000 hospitalisations per year.
However, the Te Pūnaha Matatini modellers say the higher the level of vaccination across the country, the lower the need for higher alert levels.
Professor Michael Plank says if New Zealand can lift its vaccination rates well over 90 percent of over 12s, the virus can be controlled with more sustainable measures.
Those include testing, contact tracing, and mask use.
About 73 percent of the country's eligible population has currently received one dose of the Pfizer vaccine.
Modelling work from Te Pūnaha Matatini in June showed vaccination alone would not be enough to protect new Zealand entirely, requiring other public health measures.
That has now been updated to reflect that the country could achieve 90 percent vaccine coverage across the total population.
Since the June work, the vaccine has been approved for use in Aotearoa for 12-15 year olds, with recent announcements from pharmaceutical companies suggesting that Covid-19 vaccines may soon be approved for use in children aged 5 - 11 years.
Dr Rachelle Binny said the modelling results released today showed the importance of reaching the highest possible vaccination rate.
"If nearly every New Zealander gets the vaccine, we could avoid the need for strict alert level 3 - 4 restrictions.
"The alternative is bleak. Failing to reach these high levels of vaccination would mean we will need to keep relying on lockdowns and tight border restrictions to avoid thousands of fatalities. This could cripple our healthcare system, and Māori and Pacific communities would bear the brunt of this health burden."
Covid-19 modeller Shaun Hendy said because Delta was so transmissible, population immunity was probably out of reach through vaccination alone and additional health measures will be needed combination of masks, better ventilation and vaccine certificates.
He said if vaccination only reaches 80 percent, this could result in 60,000 hospitalisations in a one year period and 7000 fatalities.
He said the health sector wouldn't be able to cope and lockdowns will likely still be needed
"If we can get up into that 90 percent rate then we can say goodbye to lockdowns."