Sweden halts use of Moderna vaccine for young adults

Neighbouring Norway and Denmark also on Wednesday reiterated that Moderna's vaccine was not recommended for under-18s.

Sweden's health agency said the suspension concerned anyone born after 1991 and should initially be in force until December 1, explaining that it had received evidence of an increased risk of side effects such as inflammation of the heart muscle (myocarditis) and inflammation of the pericardium (pericarditis).

"The Public Health Agency has decided to pause the use of Moderna's vaccine Spikevax, for everyone born 1991 and after, for cautionary reasons," the agency said in a statement, adding that those groups should instead receive the Pfizer/BioNTech vaccine.

According to the agency, the risk seems especially tied to the second dose of the Moderna vaccine and is more prevalent among young men and boys, and in the weeks just following the second jab.

The symptoms usually pass by themselves, but should be evaluated by a doctor, it added.

The health agency's recommendations provide guidance for Sweden's regional healthcare districts and are generally followed.

Some 81,000 people in the age group have already received a first jab in Sweden, but they will not be offered a second, the agency said, adding that "discussions were ongoing about the best solution for this group."

In Denmark, the vaccination programme for those aged 12 to 17 currently only offers Pfizer/BioNTech's Comirnaty vaccine but the country's health authority said Wednesday this practice would be formalised.

The Norwegian Institute of Public Health (NIPH) reiterated its recommendation to vaccinate under-18s only with Comirnaty, but added on Wednesday that men under 30 should also consider choosing the Pfizer/BioNTech jab when getting vaccinated.

The European Medicines Agency (EMA) authorised the emergency use of Moderna's Covid-19 vaccine for teens in July.