A Dunedin man whose death is linked to the Covid-19 vaccine was not warned of the risk of myocarditis, an inquest into his death has heard.

Rory Nairn died last November, less than a fortnight after receiving his first Pfizer dose.

A six-day inquest into his death is being held in Dunedin District Court.

The 26-year-old plumber died from myocarditis, a rare side-effect of the Pfizer vaccine.

It was not standard practice for the vaccinators at the pharmacy, where Nairn received the vaccine, to specifically warn patients about the risk of myocarditis following vaccination at the time when he received his first dose.

That was despite the Ministry of Health issuing a warning to clinicians in late August raising the risk of the rare side-effect following the death of a woman due to the condition.

The pharmacy where Nairn received the vaccine, as well as its owner, and the vaccinator who administered the dose have name suppression.

The pharmacy's owner admitted she had missed the August warning about myocarditis and pericarditis, and would have changed their practice to warn patients about the risk if she had been aware of it.

The vaccinator, who administered Nairn's vaccine, tearfully told the inquest the practices surrounding informed consent at the pharmacy changed immediately following his death.

"As soon as we were notified all practices were changed. It's just unfortunate that Mr Nairn had to pass away for that to happen," she said, choking back tears.

"But our practice changed and we were informing everyone that you must go to the doctor or the hospital as soon as anything happens, regardless of if you've had a vaccine or not."

Beatrix Woodhouse, the lawyer for Nairn's partner Ashleigh Wilson, told the vaccinator her client wanted her to know she did not want the vaccinator to feel any blame.

Wilson gave evidence at the inquest this morning.

She placed a photo of Nairn at the front of the courtroom, along with his wedding ring and a cast of their hands together.

"I met Rory when I was 14 years old. Rory was my first boyfriend," Wilson said.

After dating for a couple of years, the couple spent some time apart but rekindled their romance when Wilson was 21.

"Rory and I were experiencing the happiest time of our lives. We had just purchased our house and were due to be married in March 2022, and were hoping to try for a baby after the wedding.

"I went from planning a wedding to planning a funeral.

"Rory and I had our whole lives in front of us and so much to look forward to and now that's all gone."

Nairn was initially hesitant about getting the vaccine but he was concerned about the restrictions the mandates would impose on his life, particularly due to his upcoming marriage, Wilson said.

He attended a walk-in vaccination clinic on 5 November following a celebratory breakfast to mark the purchase of their new home.

Wilson described the decision as the "worst ... of our lives".

He experienced heart flutters that evening and the next night, but put it down to stress due to the new home and upcoming wedding.

Early on 17 November, Nairn woke with discomfort in his chest and agreed with Wilson to see his GP in the morning.

Several hours later, she awoke to find him getting out of bed and convinced him to go to the hospital.

Nairn collapsed in the bathroom, and lay blocking the door so she was unable to open it to reach him. He could not be resuscitated when emergency services arrived.

Wilson said she found a screenshot on Nairn's phone, following his death, detailing the risk of myocarditis following vaccination.

The screenshot was taken in the hours before his death, and if the warning was more urgent it might have saved his life, she said.

The inquest also heard from Nairn's father Brett.

He recalled his son raising the feeling in his chest in the days following his vaccination, but he "wasn't unwell".

"I don't think he thought he had anything wrong with him."

Brett Nairn knew of the risk of myocarditis and raised it with his son.

The inquest will hear evidence from witnesses from the Ministry of Health, Southern DHB - now Te Whatu Ora, and MedSafe as well as pathologist Dr Noelyn Hung.

It is set down for two days this week and four next week.

The Covid-19 Vaccine Independent Safety Monitoring Board determined late last year the vaccine likely caused his condition.

The board's role was to consider the likelihood of medical events being linked to the vaccine, but it could not make a formal ruling about the cause of death, because that sat with the coroner.

"Some Covid-19 vaccines, including the Pfizer vaccine, increase the risk of myocarditis... [but] Covid-19 infection increases the risk of myocarditis substantially more than vaccination with the Pfizer vaccine," the board said.

It also noted myocarditis was treatable, with better outcomes the earlier treatment begins.

About 95 people with myocarditis are seen in hospitals each year.

It is a rare disease caused by many things, including viral infection.

-RNZ.