Covid-19 Vaccination rates have plateaued since September. Photo: RNZ / Angus Dreaver

About 600,000 doses of the Pfizer Covid-19 vaccine are set to expire at the end of January, and its likely the vast majority will be unused by then.

Vaccination rates have plateaued since September despite a third Omicron Covid wave that could cause record hospitalisations.

Figures from Te Whatu Ora/Health NZ show small batches of doses with expiring throughout January, leading up to a batch of 592,000 that expires on 31 January.

About 64,000 vaccinations are given out each month at the moment.

There is a chance the whole pile will not go to waste, with Ministry of Health asking Pfizer if it is possible to extend the expiry date of some batches.

Medsafe will review any evidence to support that.

Vaccinologist Helen Petousis-Harris said more was known about the longevity of the vaccine than when the dates were first set.

“As more information accumulates about it, the dates can often be extended because, of course, just because a date rolls around the product instant expires and becomes useless on that date,” she said.

Covid cases are still rising, with this wave set to peak at the end of the month.

There has been little change to vaccination rates as a result, with just 46 percent of those over 50 having had their second booster.

Te Whatu Ora immunisation programme operations manager Rachel Mackay said vaccination rates were generally strong across Aotearoa but there was room for improvement especially in groups more vulnerable to the disease.

“In particular, we are striving for greater booster uptake among groups more susceptible to hospitalisation from Covid-19, including Māori, older people, and those with underlying health conditions,” she said.

Petousis-Harris said there were likely several reasons for the stalled booster uptake, including a degree of vaccination fatigue.

But it could also be because so many people were getting the virus at the moment or had recently had the virus.

On 14 December the country had about 3.7 million doses stockpiled. Another batch of about 600,000 was set to expire on 31 March 2023.

There is a new dominant Covid-19 variant for the first time since July, as health officials warn holidaymakers to take precautions.

In an update today, the Ministry of Health said there were 42,740 new cases of Covid-19 and 64 deaths of people with the virus over the past week.

BA.2.75, which is a strain of Omicron, now makes up 39 percent of genetically sequenced cases, and more than half of the cases in wastewater samples.

It has surpassed BA.5 which was the main variant for five-and-a-half months and drove the second wave in winter.

The ministry said BA.2.75 looked like it was more transmissible and could evade immunity from other variants but more data was needed to be certain.

There is no sign it is causes a more dangerous or severe illness.

The government is urging people to be prepared in case they catch Covid-19 while on holiday.

Healthcare professionals in holiday hotspots are bracing for an influx of Covid-19 patients, with one modeller warning Christmas week could see one-in-20 people infected.

Covid-19 Response Minister Ayesha Verrall said people who were eligible for a booster should get one.

She was also reminding people if they tested positive, they had to isolate for seven days.

It was important everyone played their part, she said.