A Māori health expert is calling on the Government to "taihoa" (wait) before beginning the general vaccination rollout, with just 10 per cent of vulnerable groups currently fully vaccinated.
The numbers are even more dire for Māori, with just 7.6 per cent fully vaccinated overall, compared to the national average of 12.1 per cent.
The first cohort of group 4 – those aged 60 and over – will be invited to book their Covid-19 shots from this Wednesday.
Meanwhile just under 180,000 of the roughly 1.7 million people estimated to be in group 3 - those over 65 and vulnerable groups - or just over 10 per cent were fully vaccinated.
About 17 per cent had received at least one dose.
Māori health expert and GP Dr Rawiri McKree Jansen said it didn't make sense to move on to the general population with group 3 so far behind.
"They need to taihoa. Supply was challenging for a while and they needed to build up capacity before being able to ramp up.
"I think they could wait a week or two to really reach out and boost the numbers in those vulnerable groups.
"I think it is political, about being able to deliver on their earlier assertions about how the rollout would progress."
Jansen quit the Government's expert immunisation advisory group in April, saying he considered it an "overwhelming failure" on his part and the Government's the vaccine rollout did not prioritise Māori below 65.
Despite expert advice, the Government rejected a recommendation to prioritise vaccinating Māori and Pasifika aged 50 and over, instead keeping the age group priority group at 65 and over for everyone. There are an estimated 160,000 Māori and Pasifika aged between 50 and 64.
With people returning over the next seven days from Australia, experiencing outbreaks of the Delta variant, and even ships arriving with Covid-19 on board, Jansen said there was a "very real" chance of an outbreak here.
"I am very concerned. There are no experts who say there will not be another outbreak, and the worst time we could have another outbreak is now with the vaccination only reaching a small minority of the most vulnerable."
The Government had set the group 4 rollout start date as "from July" back in March.
The Health Ministry was accused in May of quietly changing the timeline from "from July" to "from the end of July", without publicising the change.
It was criticised again when the wording for group 4 was changed from "being vaccinated from 28 July" to "they will be able to book their vaccinations from 28 July".
National's Covid-19 spokesman Chris Bishop too said the Government should hold off on the general rollout to boost rates for vulnerable groups.
"I just want to see jabs in arms but I also want to make sure those who are more vulnerable to Covid-19 get the vacccine first. At the moment the balance is not right. If it takes a delay of two to three weeks then so be it.
"But I think it is pretty clear the Government is determined to stick to that timeline given it has already changed the date on multiple occasions."
Bishop said the looming threat of Delta made vaccinating the vulnerable quickly all the more important.
"I have been very worried for a long time about Delta. The best protection is vaccination and the simple reality is we are the slowest in the western world and that puts us at risk."
University of Auckland vaccinologist professor Associate Professor Helen Petousis-Harris said the low rates for group 3 were "concerning", but she was not sure pausing the general rollout would help.
The rollout was quite uneven across the country, meaning some areas had more capacity to get started than others.
Many in group 3 - including herself - did not even realise they were in that group.
The key would be in communication between the Ministry of Health, district health boards, and health providers, she said.
"I think the focus needs to be better on identifying those who need to be vaccinated and reaching out to them, rather than necessarily pausing group 4 as in reality the goal is to get as much vaccinated as possible."
Prime Minister Jacinda Ardern told RNZ the proportion of those in group 3 vaccinated varied between district health boards, and that the group vaccinations could be done concurrently.
"No-one is going to miss out."
She said this was not about saving face because the Government had already committed to this date.
"This is always the point at which we said our programme would be ramping up."
"We had a million doses delivered in July, the next month [it will be] 1.5 million. We need to continue to book people through the system so we can keep scaling up our programme which is why we continue to roll through those groups."
Ministry of Health Covid-19 vaccination programme's Astrid Koornneef said they expected group 3 vaccinations to increase significantly in the weeks ahead.
Currently there were more than 835,000 scheduled bookings in Book My Vaccine, the national booking system, and a significant proportion of these would be for group 3, Koornneef said.
"Based on the volume of bookings in the system, and our plan to administer up to 250,000-300,000 doses a week, we expect the group 3 numbers will increase significantly in the weeks ahead."
Most of the group 4 bookings from Wednesday would come in after those already booked in group 3, he said.