Medicine /

FDA Delays Approving Moderna Vaccine for Teens

The agency cited international reports of adverse cardiovascular side effects


Biotechnology company Moderna announced the Food and Drug Administration is unlikely to approve its COVID-19 vaccine for teens before January.

In an Oct. 31 statement, Moderna said the agency needed more time to review the risk of cardiac side effects.

Several countries, including Japan, Finland, Denmark, and Sweden, have halted use of the company’s vaccine after reports of myocarditis and pericarditis surfaced. This inflammation of the heart muscle or the lining around the heart was particularly prevalent in men ages 18 to 30. 

The agency told the vaccine maker Friday evening it needed more time to analyze emerging international data on the risk of myocarditis, an inflammation of the heart muscle that in rare instances occurs after vaccination,” per The Washington Post.

The company added:

It is estimated that over 1.5 million adolescents have received the Moderna COVID-19 vaccine. To date, the observed rate of myocarditis reports in those less than 18 years of age in Moderna’s global safety database does not suggest an increased risk of myocarditis in this population. Moderna is committed to conducting its own careful review of new external analyses as they become available.”

The Center for Disease Control and Prevention said it is “actively monitoring reports of myocarditis and pericarditis after COVID-19 vaccination” by reviewing medical records and data. The agency notes myocarditis has been reported “after mRNA COVID-19 vaccination” like those made by Pfizer-BioNTech or Moderna — “especially in male adolescents and young adults.”

The inflammation is more likely to occur after the second dose and often several days after vaccination. Symptoms include chest pain, shortness of breath and feelings of having a fast-beating, fluttering or pounding heart.

Currently, Moderna’s shot is approved for adults over the age of 18. It is a two-dose regime, administered 28 days apart. Each shot is 100 micrograms.

Moderna has also asked the FDA to approve a half dose — 50 microgram — regimen for children ages 6 to 11. That approval will also be delayed pending further review.

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