Officials have confirmed another incident where people getting the Pfizer COVID-19 vaccine were given the incorrect dose.
Director-General of Health Dr Ashley Bloomfield says six Bay of Plenty residents were accidentally given a diluted dose of the vaccine - which was picked up during a reconciliation process.
Dr Bloomfield told reporters all those affected have been followed up and given advice.
"This was similar to previous incidents where this has happened… People do receive a dose but it's a very diluted dose.
"Therefore, what happens… is there's a reconciliation at the end of each session and so it's picked up immediately."
Dr Bloomfield did not believe such an incident would cause mistrust in the vaccine rollout.
"These affect a small number of people in a programme that's delivered over 6.3 million vaccinations and the assurance I can provide people is the fact that these were found is a reflection of the quality assurances processes that are in place to make sure that if there is anything that could go wrong… that actually our systems are there to find them and follow up immediately," Dr Bloomfield said.
Fifteen Wellington residents given 'expired vaccines'
Dr Bloomfield also confirmed there was an instance where 15 people were given expired doses of the Pfizer vaccine in Wellington.
The doses had passed the 30-day expiry period but not by more than 24 hours, Dr Bloomfield said.
"It had been in the 2-8C special fridge but it had just passed that 30-day period. Those people have been contacted and encouraged to get a further vaccine."
Ministry of Health COVID-19 vaccination programme national director Jo Gibbs said no one was harmed from receiving the expired doses.
"The ministry apologises for what has happened and reassures the public that such incidents are not common."