Myocarditis; This literature-non-study case was reported in a literature article and describes the occurrence of MYOCARDITIS (Myocarditis) in a 45-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 second dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date,  after starting mRNA-1273 (Spikevax), the patient experienced MYOCARDITIS (Myocarditis) (seriousness criteria hospitalization and medically significant). The patient was treated with CARVEDILOL (COREG) for Adverse event, at an unspecified dose and frequency; COLCHICINE for Adverse event, at an unspecified dose and frequency and LISINOPRIL for Adverse event, at an unspecified dose and frequency. At the time of the report, MYOCARDITIS (Myocarditis) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood pressure systolic: reduced 50% mildly reduced systolic function 50% Subsequent. On an unknown date, C-reactive protein: 25.8 25.8. On an unknown date, Catheterisation cardiac: nonobstructive cad Emergent cardiac catheterization nonobstructive CAD. On an unknown date, Ejection fraction: 40% with mild hypokinesis EF 40% with mild hypokinesis in apical segments and ef 60% EF 60%. On an unknown date, Electrocardiogram: st elevations ST elevations in leads V2-V4. On an unknown date, Electrocardiogram ambulatory: no arrhythmia no arrhythmia. On an unknown date, Magnetic resonance imaging: multifocal mid-myocardial and subepicardial late multifocal mid-myocardial and subepicardial late gadolinium enhancement in apical and basal segments consistent with myocarditis. On an unknown date, Troponin: 4.37 4.37 (peaked at 7.3) and 7.3 4.37 (peaked at 7.3).     For mRNA-1273 (Spikevax) (Unknown), the reporter considered MYOCARDITIS (Myocarditis) to be related.    No concomitant medication were reported.  Patient experienced symptom was acute sharp midsternal chest pain associated dyspnea and diaphoresis. Symptoms resolved and patient was discharged with avoidance of strenuous activity. Symptomatology was improved on first follow up.  Patient had presyncope after two weeks on second follow up. The patient was asymptomatic and exercise tolerant after two months.  Company comment: This spontaneous case concerns a 45 year old male patient with no reported medical history, who experienced the expected serious (hospitalization, important medical event) AESI of Myocarditis, 3 days after receiving the second dose of mRNA-1273 vaccine. Patient had acute onset sharp midsternal chest pain associated with dyspnea and diaphoresis. Electrocardiography showed ST-T changes and echocardiography showed reduced ejection fraction. Cardiac imaging was consistent with myocarditis. Patient was started on carvedilol, colchicine and lisinopril. Symptoms resolved and patient was discharged. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case concerns a 45 year old male patient with no reported medical history, who experienced the expected serious (hospitalization, important medical event) AESI of Myocarditis, 3 days after receiving the second dose of mRNA-1273 vaccine. Patient had acute onset sharp midsternal chest pain associated with dyspnea and diaphoresis. Electrocardiography showed ST-T changes and echocardiography showed reduced ejection fraction. Cardiac imaging was consistent with myocarditis. Patient was started on carvedilol, colchicine and lisinopril. Symptoms resolved and patient was discharged. The benefit-risk relationship of mRNA-1273 is not affected by this report.