The inquest into the death of a Dunedin man linked to the Covid-19 vaccine will start this morning.

Rory Nairn died in November last year, less than a fortnight after receiving his first dose of the Pfizer vaccine.

The 26-year-old likely died from myocarditis, a rare possible side-effect following the Pfizer vaccine.

Coroner Sue Johnson will hear evidence in the Dunedin District Court over six days to determine the cause of Nairn's death.

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

The board's role is to consider the likelihood of medical events being linked to the vaccine, but it can't make a formal ruling about the cause of death, as that sits 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 says.

It also noted myocarditis is 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.