> All were doing well clinically with resolution of their symptoms in most. Seven patients (13%) reported non-specific symptoms including intermittent atypica

> All were doing well clinically with resolution of their symptoms in most. Seven patients (13%) reported non-specific symptoms including intermittent atypical chest pain (4), palpitations (2) and mild fatigue with minimal activity (1). All patients had normal ventricular function, based on echocardiography. The 4 patients who had presented with arrhythmias earlier continue to be in normal sinus rhythm with no recurrence. > Follow up CMR studies have been scheduled and are pending at the time of this submission for rest of the patients. There were no acute events, re- hospitalization or deaths reported. > Although myocarditis following immunizations against smallpox, influenza, and tetanus is well recognized, 13-16 the experience in children with vaccine associated myocarditis, other than following COVID-19 vaccination is limited. Importantly, myocarditis was not reported following the clinical trials of mRNA COVID-19 vaccines.17,18 This may be related to the limited number of patients in the clinical trials and reflective of the apparent rarity of this complication.19 > The present study adds the following information to our understanding of myocarditis related to the COVID-19 vaccine: 1. Myocarditis following mRNA vaccines is associated with acute myocardial injury and edema of the myocardium, in the presence of preserved ventricular function. 2. The initial clinical course and short-term outcomes are good and reassuring. 3. There is no apparent difference in clinical characteristics and outcomes between 12–15- year-olds and older adolescents. 4. The clinical picture is distinct from multisystem inflammatory syndrome in children (MIS- C) and appears to be less severe. > Limitations of our study include its retrospective nature, combining patients from 16 different institutions which used similar, but not identical approaches during the work-up and management of childhood myocarditis. Our cases represent a selected cohort which may not necessarily be representative of the general pediatric population. Also, preprint despite being through peer-review might change their conclusions based on the fact that the discussion section conflicts, low N values, etc. Seems less of a problem than the blood-clots, though should be something doctors be aware of while vaccinating children to be certain it isn't happening. Looks like it's being treated successfully and heals appropriately, though, with existing medicine.