Importantly, the study found no cases of myocarditis, or inflammation of the heart muscle. This does not mean that myocarditis won’t surface among a much larger group of children. As the FDA advisers reviewed in extensive detail, myocarditis is a known adverse reaction associated with the Pfizer and Moderna vaccines, and is most prevalent in young males under 30. Myocarditis cases associated with the vaccines tend to be mild and resolve on their own, with the majority having no long-term effects. Medical groups have resoundingly noted that the benefit of the vaccine far outweighs the risk of myocarditis in adolescents.