Some Aucklanders are being told they cannot book their Covid vaccine at community vaccination centres until as late as the end of July.

However, those in charge of Auckland's rollout maintain there is "further availability" across Auckland centres and were investigating any issues with extensive booking delays.

Peter Donnelly spoke to the NZ Herald late last month, protesting the slow rollout to rest homes which forced him to take his brother, Michael, who lives with Parkinson's disease, out of the West Harbour Gardens rest home to get vaccinated in Westgate on May 21.

Donnelly was also vaccinated that day without a booking. However, upon leaving he was given a Covid vaccine record card which said he would get his second dose on June 11.

As there was no appointment time stated and he hadn't been contacted, Donnelly rang the Covid helpline on Tuesday only to find his personal details - which had been recorded by staff on May 21 - had vanished from the system and there was no booking for his second dose.

He was then presented with possible appointment options at various Auckland sites:

• Manurewa: July 6
• Mt Wellington: July 15
• Westgate: July 18
• Henderson: July 19
• Birkenhead: July 28

Frustrated but committed to becoming fully vaccinated, Donnelly accepted the Manurewa booking despite the 42-kilometre trip it would take from his home.

After the Herald contacted the Northern Region Health Co-ordination Centre (NRHCC) on Donnelly's behalf, he was called by vaccination booking staff late this week and now has a new appointment for Monday at midday in Westgate.

Despite being happy to have an earlier appointment, Donnelly was appalled with how many hiccups he had experienced on his path to becoming vaccinated.

"It's a shambles, it's a shambles," he said.

Donnelly anticipated anyone less savvy with technology or less persistence to follow up with vaccination booking staff would find the process "terribly difficult and really frustrating".

"That's all you can say and every day we hear that the Ministry of Health is beating the [vaccination] targets. Well, I don't know who set the targets."

When the Herald called the Covid helpline, a staff member noted people with appointments should be able to secure an appointment within a couple of weeks, but longer for people without bookings.

Donnelly's story comes after multiple letter writers to the Herald detailed similar accounts of vaccination sites being booked out until mid to late July.

A NRHCC spokesperson said investigations into Donnelly's experience were ongoing. They could not confirm how long Auckland's vaccination centres were booked up for, citing the ever-changing nature of bookings.

On Thursday, the Herald reported Auckland was almost 30,000 vaccines or 10 per cent behind its rollout schedule. The week prior, the city's three DHBs were 9 per cent behind - almost 23,000 vaccines.

Covid-19 response minister Chris Hipkins said on Thursday he didn't have any particular concerns at that point.

Auckland University vaccinologist Dr Helen Petousis-Harris said it was too early to know if there was a problem with the rollout in the Auckland region.

"Certainly anecdotally there are challenges but to be honest it's hard to get any clarity."

As at Thursday, about 500,000 people across the country have now had one dose, and more than 276,000 people are fully vaccinated. Overall, the rollout is about 10 per cent ahead of its delivery target.

However, also on Thursday, the Otago Daily Times anonymously quoted a senior clinician who claimed vaccine stocks were low across the country.

In the week ending June 6, New Zealand had 189,660 doses of vaccine available for distribution, down from 288,000 the previous week and 327,240 the week before that.