‘So far, the regulators haven’t determined whether there is an elevated risk,’ reports the Wall Street Journal.

The FDA is pausing approval of Moderna’s Covid-19 vaccine until it investigates cases of myocarditis in adolescents, the Wall Street Journal reports.

According to an anonymous source, the federal regulatory agency is investigating whether the mRNA jab could lead to higher incidences of the supposedly rare side effect, described as an “inflammation of the heart muscle” by the Mayo Clinic, after several Nordic countries recommended against Moderna’s use in young children. 

From the WSJ:

The Food and Drug Administration is delaying a decision on authorizing Moderna Inc.’s MRNA -2.31% Covid-19 vaccine for adolescents to assess whether the shot may lead to heightened risk of a rare inflammatory heart condition, according to people familiar with the matter.

After four Nordic countries strengthened their stances against giving Moderna vaccines to younger adults last week, the FDA has been taking another look at the risk of the condition, known as myocarditis, among younger men who took Moderna’s vaccine, especially compared with those who received the vaccine from Pfizer Inc. PFE -0.43% and BioNTech SE, BNTX -1.06% the people said.

So far, the regulators haven’t determined whether there is an elevated risk, the people said. The delay could be several weeks, but the timing is unclear, one of the people said.

Myocarditis cases are reportedly contributing to vaccine-hesitant skepticism over the vaccine.

The Journal notes regulators are being extra cautious after several European countries halted the AstraZeneca vaccine rollout over heart complication issues, with Johnson & Johnson’s Covid vaccine showing similar issues in the US.

“The European Medicines Agency safety database recorded three times as many reports of myocarditis among Moderna vaccine recipients than Pfizer-BioNTech recipients, according to a Wall Street Journal analysis of reports through Oct. 14.,” reports the Journal.

In spite of this, “Both the Moderna and Pfizer-BioNTech vaccines are cleared for use in people 12 years and older by medicines regulators in the European Union and U.K.,” the Journal reports.

While Moderna’s shot is still pending FDA approval, the Pfizer-BioNTech jab remains the only injection with to be approved for 12 to 17-year-olds, despite the jab prompting several cases of the exact same heart condition.

At the same time, an FDA panel has gone ahead and green-lighted Moderna’s use as a booster shot for “at-risk adults.”