• In June, Moderna requested emergency use authorization for use of its COVID-19 vaccine in teenagers.
• The FDA assessment may not be completed until next year.
• The issue at the center of this assessment is myocarditis (inflammation of the heart muscle). COVID-19 itself can also cause myocarditis, but there's been a recurring concern about this rare side effect in younger people - particularly young men and boys - in relation to the vaccine. Here's the note from Moderna: On Friday evening, the FDA informed Moderna that the agency requires additional time to evaluate recent international analyses of the risk of myocarditis after vaccination.
• Pfizer has FDA approval for use of its vaccine in those 16 and older, and emergency use authorization for their vaccine for those 5-15.

Why It Matters: This announcement by Moderna comes as the CDC is looking to issue guidance for the Pfizer COVID-19 vaccine in those 5-11, in the wake of the FDA granting emergency use approval for the vaccine in that age group. Although Moderna and Pfizer are different drug companies with different vaccines, this announcement may raise further questions about the safety of either of these vaccines for young people.

The FDA is probing whether the Moderna vaccine can cause a rare side effect in teens