Finland will pause the use of Moderna's COVID-19 vaccine for men born in 1991 and later due to reports of a rare cardiovascular side effect, the institute for health and welfare says.
Swedish and Danish health officials had announced on Wednesday afternoon they would pause the use of the Moderna vaccine for all young adults and children.
"A Nordic study involving Finland, Sweden, Norway and Denmark found that men under the age of 30 who received Moderna Spikevax had a slightly higher risk than others of developing myocarditis," director Mika Salminen from the health institute said.
Salminen said myocarditis, which means heart muscle inflammation, usually heals on its own in a few days. He said as a precaution Finland would only give Pfizer's vaccine to boys and young men.
A Moderna spokesperson had said late on Wednesday that company was aware of the decisions by the Swedish and Danish regulators.
"These are typically mild cases and individuals tend to recover within a short time following standard treatment and rest. The risk of myocarditis is substantially increased for those who contract COVID-19, and vaccination is the best way to protect against this."
Regulators in the United States, EU and the World Health Organisation have also said the benefits of shots based on the mRNA technology used by Moderna -- and Pfizer-BioNTech -- in preventing COVID-19 continue to outweigh the risks.