Myocarditis; Off label use; This literature-study case was reported in a literature article and describes the occurrence of MYOCARDITIS (Myocarditis) in a 17-year-old patient of an unknown gender who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.   LITERATURE REFERENCE:      No Medical History information was reported.    On an unknown date, the patient received dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. In 2021, the patient experienced MYOCARDITIS (Myocarditis) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced OFF LABEL USE (Off label use). At the time of the report, MYOCARDITIS (Myocarditis) outcome was unknown and OFF LABEL USE (Off label use) had resolved. Possible    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Electrocardiogram: abnormal (abnormal) diffuse ST-segment elevation (days 1 and 2) and T-wave inversion (days 4 and 10). On an unknown date, Troponin: increase (High) increase.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered MYOCARDITIS (Myocarditis) to be possibly related. No further causality assessment was provided for OFF LABEL USE (Off label use).    In this retrospective multicenter study across 16 hospitals, patients <21 years of age with a diagnosis of C-VAM (coronavirus disease 2019 vaccinationassociated myocarditis) were included and compared with a cohort with multisystem inflammatory syndrome in children. Younger children with C-VAM were compared with older adolescents.  Included Sixty-nine patients with a diagnosis of acute myocarditis after COVID-19 vaccination who had presented between Mar-2021 and Jun- 2021. Fifty-nine patients (94%) had received the Pfizer-BioNTech vaccine, and 4 (6%) had received the Moderna vaccine. All except for one patient presented after the second dose.  This case concerns a 17-year-old, male patient with no relevant medical history reported, who experienced the expected serious AESI event of myocarditis. Off-label use was considered an additional event. The event occurred approximately at an unknown date after a dose of Spikevax. The rechallenge was unknown since no information about the other doses was available. The benefit-risk relationship of Spikevax is not affected by this report.   This case was linked to MOD-2021-364727 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 28-Oct-2021: Follow up received by safety on 14-Oct-2021 included an Email with report received from team and does not contain any new information.; Sender's Comments: This case concerns a 17-year-old, male patient with no relevant medical history reported, who experienced the expected serious AESI event of myocarditis. Off-label use was considered an additional event. The event occurred approximately at an unknown date after a dose of Spikevax. The rechallenge was unknown since no information about the other doses was available. The benefit-risk relationship of Spikevax is not affected by this report.