Health authorities in Sweden have suspended the use of the Moderna coronavirus vaccine for people under the age of 30 in a "precautionary" measure. The Swedish Public Health Authority stated that the use of the vaccine was suspended due to “signals of an increased risk of side effects such as inflammation of the heart muscle or the pericardium" found in a study by the Denmark’s Statens Serum Institute. “The risk of being affected is very small,” the authority noted. The decision to suspend the use of the Moderna vaccine is valid until December 1. The Pfizer coronavirus vaccine will continue to be used in its stead. At the same time, Denmark announced it would suspend the use of the Moderna vaccine for children under the age of 18, and Norway encouraged people under the age of 30 to get the Pfizer vaccine instead of the Moderna vaccine. The European Medicines Agency, the medical watchdog of the European Union, announced earlier this week that it has approved the application of coronavirus booster shots for people who have received two doses of the coronavirus vaccine. The approval applies to people over the age of 18 who received the second dose of the Pfizer or Moderna coronavirus vaccine at least six months prior. People with weakened or compromised immune systems would only have to wait 28 days after their second shot.