Professor Shaun Hendy is standing by the Government's release of data on vaccination, disease and deaths rates, saying the confronting information should be made public.
The modelling done by Te Pūnaha Matatini at the University of Auckland shows if 80 per cent of the population over the age of five is vaccinated 7000 people a year could still die from the virus and 60,000 could end up in hospital.
Even at much higher vaccination rates additional measures such as mask-wearing and rapid antigen testing would be needed to avoid lockdowns.
"We are trying to inform policy choices, so that means that the types of things we do, which is looking at things like the effects of public health measures and vaccination rates and how they can affect the outcomes," Hendy said.
New Zealand was in a unique situation compared to other countries, he said, and more at risk.
"We haven't had large numbers of infections here so we haven't banked that natural immunity like other places such as the UK have. Our population unvaccinated remains vulnerable to Covid-19."
Hendy also noted his worst-case scenario was unlikely to occur because the Government would step in before then and put some level of lockdown in place.
Hendy told RNZ people have been talking about opening up once the country hits a vaccination rate of 80 per cent.
At 80 per cent, about one million people would still be unvaccinated, he said.
"There certainly have been proposals for opening up at 80 per cent and so we should explore the consequences of that."
He said while some people will find the numbers uncomfortable, the consequences, costs and benefits of different pathways should be discussed.
"There's always uncertainty in modelling and this modelling is no exception. We're trying to use the best data from overseas, in particular the best information we have about the effectiveness of the vaccine."
He wants people to think about what kind of restrictions they could live with long term.
Wigram Capital's Rodney Jones - who has been tracking the Covid-19 numbers - said yesterday's media conference engendered fear.
"You can't fight fear with fear," he told RNZ. "If people are reluctant to get vaccinated we need to encourage them, we need to kind of explain, we need to build a narrative where they feel they're part of a process. If we scare them it doesn't work."
Jones said the modelling assumes the country would have no restrictions and questioned the credibility of the modelling, saying it did not match real-life figures overseas.
"When you see 7000 deaths it's frightening, that's 140 a week in a country like New Zealand, there is no way New Zealand would experience anything like that."
Using models for long-term modelling was not helpful, as the pandemic and people are much too complex, he said.
"This is a side-show and should be treated as such. What we know is we need to get people vaccinated and we need as many people as possible vaccinated and it is true through vaccination we can live the best possible life in New Zealand.
"That's the message we need to get across and that is a message of hope, not of fear," he said.
"It's actually time for modelling to step back. Modelling was great early in the outbreak but we have world experts on how to manage outbreaks.
"This is a highly technical field and so people with expertise who have jumped in, like myself and like Shaun, it's time for us to step back."
People who study outbreaks full-time need to lead the discussion, he said.
"This is complicated."
Intensive care doctor Andrew Stapleton supported the data being made public, given the impact lower vaccination rates could have on hospitals.
"It represents approximately 12,000 patients who would need ICU based on the UK data, which would be one patient per every ICU bed in New Zealand every week for 52 weeks.
"This would mean we would have to move to our crisis staffing model and the resulting avoidable deaths would be very high," he said.
There is one thing all the experts agree on - the country needs to vaccinate as many people as possible.