An Auckland vaccination centre may have to cut the number of days it operates unless it gets more vaccinators.
Each nurse at the Ōtara site is delivering about 100 injections a day at the centre, which runs seven days a week.
Those in charge said they urgently need more vaccinators to prevent nurses getting exhausted and to keep up the momentum of the great community response.
South Seas Health Care chief executive Lemalu Silao Vaisola-Sefo, who runs the centre with a group of Pacific providers, said the centre was initially set up to reach about 300 people a day.
But most days they were vaccinating nearly 400, with about four nurses.
"It's not a great ratio," he said.
The staff were coping thanks to the great support they gave each other but, unless they got help soon, something would have to change, he said.
One option was to stop running every day.
The centre has been promised new vaccinators for July, when the rollout was really due to get cranking.
But they were needed sooner, and could do even more vaccinations if they had them, Vaisola-Sefo said.
He worried the campaign could lose momentum if they could not meet demand.
"There's energy from the community now to come forward so we've got to meet that; otherwise, we'll almost have to have another campaign later in the year," he said
They were waiting for the so-called non-regulated vaccinators, people from non-medical backgrounds, who were being trained up on behalf of the Ministry of Health.
Health Star Medical Centre chief executive Vaifagaloa Naseri runs the team of vaccinators and said they urgently needed new ones - to give the current workers a break.
Many were borrowed from other clinics, did a few intense days at the vaccination centre, then went back to do all their regular work.
There was a particular need for more Pacific vaccinators.
That was especially important if those getting their jabs were feeling nervous, she said.
"Some of them, they are strong to come through, but then ... they still need that reassurance - even at the last minute before the needle goes in," she said.
The Pacific vibe meant the centre was very family friendly and would often take the opportunity to vaccinate family members who came in to support the person who had an appointment.
Auckland woman Lote brought her grandmother in to be vaccinated but ended up receiving the vaccine too.
"I wasn't thinking to have my vaccine before [I came] but it's good to have one," she said.
Despite the Pacific kaupapa, the clinic was for anyone and was busy the day RNZ visited.
Vaisola-Sefo said the city's District Health Boards had been very supportive.
They had also been urging the ministry to get the non-regulated vaccinators out to clinics as soon as possible, saying last month they were more than 1000 short across the city.
The ministry said a pilot training programme for the non-regulated vaccinators was due to start, with most set to be trained in June, ready for the second half of the year when they were most needed.