On Wednesday, Sweden and Denmark said they are pausing the use of Moderna’s Covid vaccine for younger age groups after reports of possible rare cardiovascular side effects. The Swedish health agency said it would pause using the shot for people born in 1991 and later as data pointed to an increase of myocarditis and pericarditis. Those conditions involve an inflammation of the heart. A Moderna spokesman said: “These are typically mild cases and individuals tend to recover within a short time. The risk of myocarditis is increased for those who contract Covid, and vaccination is the best way to protect against this.” Denmark said it has paused the vaccine for those below 18 according to “precautionary principle”.