The death is New Zealand’s second linked to a known but rare side effect from the vaccine after health authorities in August reported a woman had died after taking her doses.
“With the current available information, the board has considered that the myocarditis was probably due to vaccination in this individual,” a Covid-19 Vaccine Independent Safety Monitoring Board said in a statement on Monday.
The man, who died within two weeks of his first dose, had not sought medical advice or treatment for his symptoms.
Myocarditis is an inflammation of the heart muscle that can limit the organ’s ability to pump blood and can cause changes in heartbeat rhythms.
A Pfizer spokesperson said the company was aware of the report of the death in New Zealand, it monitored all reports of possible adverse events, and continued to believe the benefit-risk profile for its vaccine was positive.
In the UK, there have been three deaths involving myocarditis or pericarditis – inflammation of the outer lining of the heart – linked to the Pfizer vaccine, and two connected to the AstraZeneca jab.
New Zealand’s vaccine safety board also said another two people, including a 13-year-old, had died with possible myocarditis after taking their vaccinations. More details were needed before linking the child’s death to the vaccine, while the death of a man in his 60s was unlikely related to the vaccine, it said.
Despite the rare side effects, the vaccine safety board said the benefits of vaccination greatly outweighed the risks.
New Zealand’s health regulator Medsafe granted provisional approval last week for the Pfizer vaccine for children aged five to 11.
In other developments, thousands of people marched in New Zealand’s capital Wellington last Thursday to protest against Covid-19 vaccine mandates and lockdowns, as the country reached the 90pc fully vaccinated milestone.
New Zealand’s tough lockdown and vaccination drives have helped keep coronavirus infections and related deaths low, but it has also drawn criticism from some calling for more freedoms and an end to mandatory vaccine requirements.
The government has mandated vaccinations for teachers, workers in the health and disability sectors, police and other public service sectors.