"High-risk" New Zealanders are being given an extra two weeks to get their flu vaccine which means the wider public will have to wait until April 28.
The extension comes after some private providers were found to be stockpiling doses while others were running out, an issue Associate Health Minister Julie Ann Genter said was "unfortunate" and "disappointing".
Today, Genter announced an extra 300,000 doses had arrived in the country and were being distributed in addition to the 900,000 vaccines already sent out to GPs and pharmacies.
"We have intervened to ensure that every provider has enough stock for their priority groups."
The stockpilers intending to sell the vaccines to the private sector had now been ordered to redistribute it so people at risk of serious illness can be vaccinated.
Priority groups now had until April 27 to get their influenza vaccine before the wider public would be able to, that includes:
• People aged 65 and over
• People who are pregnant
• People with certain chronic conditions, and
• Young children with a history of severe respiratory illness
• Frontline health workers
"Ensuring high-risk groups are getting the flu vaccine could literally save lives, we don't want people getting sick and ending up in hospital.
"People most at risk of getting the flu are also those most at risk of getting Covid-19, the flu shot won't protect you from Covid-19 but it will protect you from the flu and the less sick people we have in hospital this winter the better."
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Genter said she was confident New Zealand now had enough supply for those priority groups, so long as providers played ball.
She urged vaccine providers to "please prioritise the most vulnerable groups" as it would ensure the best outcome for all New Zealanders.
"There is no point vaccines sitting around unused.
"Any health provider that does not have sufficient supply for priority groups is encouraged to contact their DHB Immunisation Co-ordinator so more stock can be arranged."
Genter said the Ministry of Health would be actively managing flu vaccine stocks to ensure priority groups can access them and they are going where they are most needed.
Doses can now only be ordered 60 at a time.
Genter said she wanted to be clear that hospital cleaners, aged-care workers and home support workers were a priority for accessing flu vaccines during this time.
"We are working with employers to make sure this is provided at no cost to them.
"With our borders shut and the country in lockdown we expect fewer transmissions of influenza."
On Monday, Director General of Health Ashley Bloomfield said when the first reports of a shortage came in, they knew 500,000 hadn't been used.
When a vaccine is administered, it's registered with the Immunisation Advisory Centre.
"We're playing an active role in ensuring they're redistributed around the country," he said.
In an email from the Ministry of Health to vaccine providers seen by the Herald, it said the issue with supply was stockpiling.
"It has been brought to our attention that a number of wholesalers, travel and occupational health providers have ordered a large quantity of influenza vaccinations ahead of the vaccine becoming available for use in the private market.
"Because of this stockpiling, some providers are having difficulty vaccinating those at risk of serious illness."