Next year could be the year of Covid-19 outbreaks in New Zealand, according to one of the country's medical officers of health.

Speaking in a personal capacity, Waikato DHB medical officer of health Richard Hoskins told an audience at a vaccine forum at Waikato University on Monday night that last year was the year of Covid - and this year is a focus on vaccinations.

However, he believed 2022 would be the year of Covid outbreaks in New Zealand.

"These are gross oversimplifications, but I believe 2022 onwards is going to be the year of outbreaks in Aotearoa," he said at the forum.

Hoskins confirmed the comment when approached but wouldn't be drawn on it any further instead, directing the Herald to the Ministry of Health.

A ministry spokesperson didn't comment directly either but said they would have a better idea of what 2022 looks like towards the end of the year, "when the science is clearer and the vaccination rollout has reached all groups".

The ministry was focussed on getting "as many people as possible vaccinated".

"It's important to stress also that as well as getting as many people as possible vaccinated, we'll keep using standard public health controls to stamp out outbreaks as long as Covid-19 remains a global threat."

Several government agencies were continuing to work on opening the country's borders "in a controlled and risk-responsive way", initially with the introduction of quarantine-free travel with Australia, Cook Islands and Niue.

"Professor Sir David Skegg's group is working on options to advise the Government on the safest way to open up to other countries.

"We have said all along there's unlikely to be one day when all border restrictions end, but that change will happen in stages, when it is safe to do so."

There were doubts from experts about whether New Zealand could reach the 97 per cent herd immunity threshold needed to keep Covid out of the country.

Modelling from research centre Te Pūnaha Matatini indicated 83 per cent of New Zealanders would have to be vaccinated against less transmissable virus strains for measures like lockdowns and 14-day quarantine to be no longer needed.

However, the modelling - which was yet to be peer reviewed - suggested 97 per cent of Kiwis would need both Pfizer jabs to abandon such measures if the country was hit by a wave of a strain as transmissable as the Delta variant.

Te Pūnaha Matatini professor Shaun Hendy said it was "pretty unlikely" New Zealand would reach that level of vaccine coverage.

When contacted today, epidemiologist Professor Michael Baker said he disagreed with Hoskins' sentiment and instead believed the country would reach a high vaccination rate by the end of the year, especially if children as young as 6 months were made eligible.

That would vaccinate another 20 per cent of New Zealanders - those aged between 6 months and 12 years old - bringing the number as high as 80 per cent or even up to 90 per cent.

Those aged between 12 and 15 had already been given provisional approval by Medsafe to get the vaccine.

"That is still very good coverage and does limit the spread of the virus.

"We have to speculate in the future what may happen and as we know with this virus there are many unanswered questions that will radically revise what will happen next year and how infection goes. "

Baker said Pfizer had been "very reliable" in delivering vaccines to New Zealand and enough vaccines were in the pipeline for every Kiwi.

Baker said 2022 would instead be the year of a choice for the Government as it forged its path in managing the pandemic.