Covid-19: 4.2% of Pfizer vaccines going to waste in NZ

About four of every 100 doses of our main Covid-19 vaccine are currently going to waste, officials say, on top of tens of thousands of doses discarded this year. Photo / Sylvie Whinray

About four of every 100 doses of our main Covid-19 vaccine are currently going to waste, officials say, on top of tens of thousands of doses discarded this year.

But the Ministry of Health considers that rate low, amid what's been New Zealand's largest vaccination drive in history.

New Zealand purchased nearly 11 million doses of the Pfizer vaccine last year – reportedly at a rate of about $36.50 per dose – before ordering another 4.7 million to ensure it could cover the population.

On top of that, the Government secured 10.7 million doses of the non-mRNA Novavax vaccine and 7.6 million doses of the AstraZeneca vaccine, of which fewer than 9000 of 120,000 doses were ever used before the $1.2m supply expired.

Figures recently released under the Official Information Act showed nearly 50,000 Pfizer doses were wasted between last November and April, with wastage increasing as demand fell.

The Ministry of Health couldn't tell the Herald precisely how many doses were being discarded right now, nor the cost of that wastage, citing commercial sensitivity around its arrangements.

But it did reveal the wastage rate for the primary vaccine used in the programme – also used in booster courses – was running at about 4.2 per cent.

This was based on the number of doses wasted - an average six doses per vial - divided by the number of doses administered.

The ministry's national immunisation programme director Astrid Koornneef said nearly 12 million doses of vaccines had been already administered in New Zealand, with just over 90 per cent of the population over 12 having received their first two shots.

Koornneef said that, while New Zealand was actively managing its portfolio of vaccines to maximise uptake and minimise wastage, some wastage was "inevitable".

"As with any vaccine, there are numerous reasons that could lead to Covid-19 vaccine being discarded or wasted," she said.

"These reasons for example can include doses being left unused, expiring, a cold chain breach, freezing, or human error, such as a Covid-19 vaccine vial being accidentally broken."

She said there were "robust systems and processes" in place to ensure vaccine supplies were used efficiently.

"This includes ensuring vaccines are stored at temperatures that maximise shelf life, and continuing to promote up-to-date vaccination."

Vaccines that expired were destroyed at a waste disposal facility licenced to process medical waste.

Wherever possible, Koornneef said the programme also worked to ensure surplus vaccines could be used elsewhere, with more than nine million doses donated to the Covax facility for distribution to developing countries since May last year.

It wasn't clear what the Government purchasing new vaccines, such as Omicron-targeted bivalent shots – Pfizer recently applied to MedSafe for provisional approval for their use here – would mean for our existing stock.

"Any future potential discard of current vaccines will be dependent on a number of factors, including the nature of the outbreak at the time, availability and approval of potential new vaccines, and any future changes to vaccination settings that may be required."