Pressure on vaccine supplies is forcing the rollout to be slowed down for prisoners and some Defence Force personnel, the Ministry of Health has confirmed.
It is also asking for appointments only, meaning no more walk-ins.
This contrasts to Covid-19 Response Minister Chris Hipkins' comments on Tuesday. Hipkins was asked whether the expected vaccine shipments between now and the end of July would require the rollout to be scaled down at all.
"No, we shouldn't do, based on the deliveries," Hipkins replied.
"We know we're going to get a reasonable amount through June as we finish up the deliveries that are already scheduled. We'll have a few extra doses coming through our Covax allocation during that time, and then, through July, we've now got the confirmation of a million."
Added Prime Minister Jacinda Ardern, who hosted the Tuesday press conference with Hipkins: "I breathed a sigh of relief when I got a message from Minister Hipkins telling me what July was looking like. So it will still take planning, but we don't have quite the same anxiety we had previously that we were ramping up maybe too quickly for the deliveries."
This afternoon, however, director-general of health Ashley Bloomfield confirmed that the rollout for prisoners and Defence Force personnel will be slowed down.
"Stocks will be tight for the next five weeks and we have planned carefully to manage our way through.
"As part of carefully managing our vaccine stocks over the next five weeks we are slowing, but not stopping, vaccinations planned for people in prison and some civilian and reserve Defence Force personnel."
Asked on Newstalk ZB if "we're running it to the wire", Bloomfield said: "We are, and in a way that's quite deliberate because the most important place these vaccines can be is in people's arms."
He still expected DHBs to be able to meet their delivery targets for June and July.
Walks-ins have so far been permitted to get vaccinated in order to avoid wastage, but he said that was no longer needed because the vaccine can now be safely stored at 2-8 degrees for up to 31 days.
"This means appointments will be required for vaccinations at all DHBs so we can carefully manage our supply during this period.
"Current bookings will not be affected. But DHBs are likely to have to manage the rate of new bookings to ensure they are delivering in line with their current plans."
A senior clinician, speaking anonymously, told the Otago Daily Times today that vaccine supplies were low across New Zealand.
"People giving out vaccines have been told to cut right back because there is not enough vaccine for the country to continue at the current rate.
"There is not much transparency from the Ministry of Health regarding vaccine availability."
Last week Southern District Health Board chief executive Chris Fleming also told a board meeting the region's vaccination efforts could go faster, but would need to slow down due to supply issues.
In the week ending June 6, New Zealand had 189,660 doses of vaccine available for distribution, down from 288,000 the previous week and 327,240 the week before that.
Recently about 50,000 to 60,000 vaccine doses have been arriving weekly, though the Government won't say how many weekly doses are expected, citing commercial sensitivity.
Bloomfield said people in Group 3 - those over the age of 65, people with disabilities, pregnant people and certain health conditions - were anxious to know when they will receive their vaccination.
"We have asked DHBs to ensure people in this group receive an invitation to be vaccinated by the end of July at the latest."
Vaccinations are open to people in Group 3 now, while Group 4 - the rest of the country 16 and over - is meant to start at the end of July.
Bloomfield said there will be enough weekly arrivals of vaccine shipments for DHBs to deliver 500,000 doses in the next five weeks.
On Tuesday Hipkins and Ardern confirmed the delivery of an estimated 1 million doses of vaccine during July. Most of that - about 700,000 doses – is expected in the second half of July.
Ardern said at the time that New Zealand will have received more than 1.9 million doses in total by the end of July.
The Ministry of Health clarified today that that number was closer to 2.2 million doses, and included 100,000 Covax doses.
As of midnight Tuesday, the rollout was 10 per cent ahead of schedule, but Auckland Metro - which is the region's three DHBs - were almost 30,000 jabs behind schedule.
Auckland University vaccinologist Dr Helen Petousis-Harris said it was too early to know if there was a problem with the rollout in the Auckland region.
"Certainly anecdotally there are challenges but to be honest it's hard to get any clarity."