The Canterbury District Health Board (DHB) is investigating the oversupply of 1400 doses of the COVID-19 vaccine, which were due to expire at Christchurch's Burwood Hospital.
The excess vaccines led to an impromptu roll-out, a move that was applauded by the Government - which says New Zealand's rate of vaccine waste is among the lowest in the world.
The unscheduled recipients were quick to respond to the last-minute vaccine invitations from hospital staff.
"I think some of what I've read out of Canterbury is that not only did they call those people, but those people who were called in were grateful for that opportunity," Director-General of Health Dr Ashley Bloomfield says.
The move to use the excess vaccines was endorsed by Health Minister Chris Hipkins.
"Whether it's DHBs, PHOs, or whoever is doing the vaccination finds they have some vaccines that could be about to expire if they don't use them... if they find creative ways to use them, I would not only defend that but I would encourage it," he says.
"Ultimately I don't want to have vaccinations going to waste necessarily and if that means some people who might otherwise not get a vaccine [instead] get a vaccine a bit early, I'd far rather that happen than vaccines being thrown away."
While the Canterbury DHB investigates the cause of the oversupply, the Government expects it could happen again.
"As we go through this process of scaling up, there are going to be a few more unders and overs in terms of delivery on a day-by-day basis," Hipkins says.
If prompted, DHBs are ready for an early staff rollout to avoid wastage.
"Canterbury DHB, as all DHBs, had a plan in place for if they had excess vaccines and we actually saw this play out from the very first weekend vaccinations started in Auckland," Dr Bloomfield says.
"Every DHB has a plan about how they can quickly call people in."
Meanwhile in the United States, millions of doses of the Johnson and Johnson vaccine have been paused after six women under the age of 50 who were given the vaccine developed blood clots.
Medsafe is still considering whether to approve the vaccine in New Zealand, but due to the low risk of blood clots, Dr Bloomfield is confident it won't give weight to their decision.
"I don't expect that it will prevent the Jansen vaccine potentially from being approved if that's the recommendation," he says. "But that will of course may well add to one of the requirements on the process for its approval."
The move could boost our COVID-19 vaccine rollout, which so far is the second slowest in the world.