Iceland on Friday suspended the Moderna coronavirus jabs citing a slightly increased risk of cardiac inflammation, going further than its Nordic neighbors which previously only limited the use of the vaccine.

"As the supply of Pfizer vaccine is sufficient in the territory ... the chief epidemiologist has decided not to use the Moderna vaccine in Iceland," said a statement published on the Health Directorate website.

This decision owed to "the increased incidence of myocarditis and pericarditis after vaccination with the Moderna vaccine, as well as with vaccination using Pfizer/BioNTech," the chief epidemiologist said in a statement.

For the past two months, Iceland has been administering an additional dose "almost exclusively" of the Moderna vaccine to Icelanders vaccinated with Janssen, a single-dose serum marketed by America's Johnson & Johnson, as well as to elderly and immunocompromised people who received two doses of another vaccine.

This will not affect the vaccination campaign in the island of 370,000 inhabitants, where 88% of the population over 12 years old is already fully vaccinated.

Since Thursday, Sweden and Finland have also suspended the use of the Moderna vaccine but only for those under 30, because of a risk of inflammation of the myocardium, the heart muscle, and the pericardium, the membrane covering the heart.

Denmark and Norway have formally advised against it for those under 18.

According to Swedish authorities, most of these inflammations are benign and pass on their own, but it is recommended medical advice be sought should symptoms occur.