acute myopericarditis; This literature-non-study case was reported in a literature article and describes the occurrence of MYOCARDITIS (acute myopericarditis) in an 18-year-old male patient who received mRNA-1273 (Spikevax) for COVID-19 vaccination.     No Medical History information was reported.    On an unknown date, the patient received first dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date, the patient experienced MYOCARDITIS (acute myopericarditis) (seriousness criterion medically significant). The patient was treated with COLCHICINE for Adverse event, at an unspecified dose and frequency. At the time of the report, MYOCARDITIS (acute myopericarditis) was resolving. Related    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Ejection fraction: 50-55 percent evidence of borderline reduced ejection fraction 50-55 Percent. On an unknown date, Electrocardiogram: diffuse st elevation and pr segment diffuse ST elevation and PR segment depression, with increased inflammatory markers consistent with pericarditis.. On an unknown date, Polymerase chain reaction: negative (Negative) Negative polymerase chain reaction (PCR) test for COVID-19 infection. On an unknown date, Troponin: 16 ng/ml (High) Elevation of troponin 16 ng/mL.     The action taken with mRNA-1273 (Spikevax) (Unknown) was unknown.   For mRNA-1273 (Spikevax) (Unknown), the reporter considered MYOCARDITIS (acute myopericarditis) to be related.    No concomitant medication reported. Patient experienced retrosternal chest pain after receiving a first dose of the mRNA-1273 vaccine, global left ventricular hypokinesis were suggestive of myopericarditis. Infectious and autoimmune studies were negative.  The patient was treated mainly with nonsteroidal anti-inflammatory drugs which resulted in a significant improvement of clinical symptoms  Company Comment: This is a Literature-Non-Study case concerning an 18-year-old male patient, with no reported medical history, who experienced the serious expected AESI of Myocarditis (Serious criteria Medically Significant). The event occurred in an unknown exact date, after the administration of the first dose of the mRNA-1273 vaccine. Relevant tests were performed that showed an electrocardiogram revealed diffuse ST elevation and PR segment depression, with increased inflammatory markers consistent with pericarditis. Elevation of troponin (16 ng/mL), evidence of borderline reduced ejection fraction (50-55%), and global left ventricular hypokinesis were suggestive of myopericarditis. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report. The case was assessed as serious.; Sender's Comments: This is a Literature-Non-Study case concerning an 18-year-old male patient, with no reported medical history, who experienced the serious expected AESI of Myocarditis (Serious criteria Medically Significant). The event occurred in an unknown exact date, after the administration of the first dose of the mRNA-1273 vaccine. Relevant tests were performed that showed an electrocardiogram revealed diffuse ST elevation and PR segment depression, with increased inflammatory markers consistent with pericarditis. Elevation of troponin (16 ng/mL), evidence of borderline reduced ejection fraction (50-55%), and global left ventricular hypokinesis were suggestive of myopericarditis. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report. The case was assessed as serious.