The COVID-19 Response Minister admits he has "a little bit of anxiety" over New Zealand's vaccine rollout, as DHBs continue to smash their weekly immunisation targets.
Chris Hipkins says while he's "reasonably comfortable" the country's current vaccine stock will last until the next big delivery in July, there's some fear we might run out if DHBs keep outperforming their vaccine targets "by a big margin".
If that happens over the next six weeks, he warns it could force health officials to rapidly scale down the nationwide COVID-19 immunisation programme.
"I do have a little bit of anxiety about having to scale back too severely if we were to continue to ramp-up too quickly," he said at a press conference from the Beehive on Wednesday afternoon.
"At the moment I'm feeling reasonably comfortable that where we're at, we should have enough to get us through June before those big [vaccine] deliveries arrive.
"But if the DHBs continue to outperform their targets by a big margin - and that margin continues to grow - then the risk of having a week or two where we have to scale back, that becomes a more real possibility."
At the moment, the Ministry of Health's vaccine rollout operation is tracking ahead of schedule.
By Monday, May 16, DHBs had set a collective target of having administered 414,824 coronavirus vaccine doses. The actual number of doses administered at this stage was 449,139 - more than 34,000 doses more than planned.
Hipkins says he'll feel much better when a vaccine delivery schedule is locked down.
"Beyond July, there's still some question marks around just what the delivery schedule will be - that's not locked in yet - in terms of exactly what dates and quantities are arriving," he told media.
"I'll feel much better when that's all been locked down. Those discussions are literally happening as we speak.
"It is going to be a big undertaking to ramp up steeply, to go from doing 16,000-odd [doses] at our current peak, to getting up to doing 40,000-50,000 a day - that is going to be a steep ramp-up."
On Wednesday, Hipkins announced New Zealand's COVID-19 vaccination programme would cost $1.4 billion.
The investment has been allocated over two years, to ensure every New Zealander is vaccinated against COVID-19 with the Pfizer-BioNTech jab.
More than $1 billion has been allocated for purchasing vaccines and specialist equipment, while $964.3 million is for manufacturer advance purchase agreements and to support equitable access to COVID-19 vaccines.