Myocarditis; This literature-non-study case was reported in a literature article and describes the occurrence of MYOCARDITIS (Myocarditis) in a 33-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, the patient experienced MYOCARDITIS (Myocarditis) (seriousness criteria hospitalization and medically significant). At the time of the report, MYOCARDITIS (Myocarditis) outcome was unknown. Related    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Brain natriuretic peptide: 25.4  pg/ml Initial: 25.4  pg/mL. On an unknown date, Electrocardiogram: st-segment elevations (High) Initial: ST-segment elevations and newright bundle branch block no st abn On Follow-up it showed New right bundle branch block No ST abnormality(abn). On an unknown date, Magnetic resonance imaging heart: 57 days Initial CMR after 57 days showed left ventricular ejection fraction(LVEF) of 61 %, end-systolic volume index (ESVI) of 32 mL/m2 and late gadolinium enhancement(LGE) apical septum(S)/ inferolateral(IL)/inferior(I) segments and 189 days Follow up CMR after 189 days showed  left ventricular ejection fraction(LVEF) of 63 %, end-systolic volume index (ESVI) of 19 mL/m2 and Improved with late gadolinium enhancement(LGE) in anterior(A)/ inferior(I) segments. On an unknown date, N-terminal prohormone brain natriuretic peptide: 32.2 pg/ml follow-up: 32.2 pg/mL. On an unknown date, Troponin (Unknown-less than 60.4): 8.7 ng/l (normal) follow-up: 8.7 ng/L. On an unknown date, Troponin I: 38.8 ng/ml Initial: 38.8 ng/mL.     For mRNA-1273 (Spikevax) (Unknown), the reporter considered MYOCARDITIS (Myocarditis) to be related.    Company comment: This is a literature non-study case concerns a 33-year-old, male patient with no reported medical history, who experienced the expected, serious (hospitalization, medically significant) AESI of Myocarditis. The event occurred unknown number of days after receiving the second dose of mRNA1273. The patient undergone various laboratory test including: Brain natriuretic peptide: 25.4  pg/ml Initial: 25.4  pg/mL. Electrocardiogram: st-segment elevations (High) Initial: ST-segment elevations and newright bundle branch block no st abn On Follow-up it showed New right bundle branch block No ST abnormality(abn).  Magnetic resonance imaging heart: 57 days Initial CMR after 57 days showed left ventricular ejection fraction(LVEF) of 61 %, end-systolic volume index (ESVI) of 32 mL/m2 and late gadolinium enhancement(LGE) apical septum(S)/ inferolateral(IL)/inferior(I) segments and  follow up CMR after 189 days showed  left ventricular ejection fraction(LVEF) of 63 %, end-systolic volume index (ESVI) of 19 mL/m2 and Improved with late gadolinium enhancement(LGE) in anterior(A)/ inferior(I) segments.  Several important findings were noted in the report including follow-up CMR demonstrated improved or resolved LGE in all cases;  left ventricular ejection fraction improved and end-systolic volume index decreased in all subjects; there was no evidence of ongoing active myocardial injury by CMR (edema) or hs-cTnI; and  there were no interim symptoms, impaired activity tolerance, or hospitalizations. At the time of the report there was no evidence of myocardial dysfunction or ongoing myocardial injury at intermediate-term follow-up and no subsequent adverse cardiac events. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   This case was linked to MOD-2021-297296 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 14-Apr-2022: Live Follow up received by safety on 14-Apr-2022 has Email received from team and contains Significant information: lab data updated; Reporter's Comments: Lab T1/T2, ms were 950, 47 respectively.  At the time of follow-up, all participants denied activity intolerance, chest pain, shortness of breath, or palpitations, and there were no interim major adverse cardiac events or hospitalizations. At the date of follow-up, no participant eligible for the COVID-19 vaccine booster had received it.  The clinical course of vaccine-associated myocarditis appears favorable, with resolution of presenting symptoms in all patients.  Treatment and concomitant medications were not reported.; Sender's Comments: This is a literature non-study case concerns a 33-year-old, male patient with no reported medical history, who experienced the expected, serious (hospitalization, medically significant) AESI of Myocarditis. The event occurred unknown number of days after receiving the second dose of mRNA1273. The patient undergone various laboratory test including: Brain natriuretic peptide: 25.4  pg/ml Initial: 25.4  pg/mL. Electrocardiogram: st-segment elevations (High) Initial: ST-segment elevations and newright bundle branch block no st abn On Follow-up it showed New right bundle branch block No ST abnormality(abn).  Magnetic resonance imaging heart: 57 days Initial CMR after 57 days showed left ventricular ejection fraction(LVEF) of 61 %, end-systolic volume index (ESVI) of 32 mL/m2 and late gadolinium enhancement(LGE) apical septum(S)/ inferolateral(IL)/inferior(I) segments and  follow up CMR after 189 days showed  left ventricular ejection fraction(LVEF) of 63 %, end-systolic volume index (ESVI) of 19 mL/m2 and Improved with late gadolinium enhancement(LGE) in anterior(A)/ inferior(I) segments.  Several important findings were noted in the report including follow-up CMR demonstrated improved or resolved LGE in all cases;  left ventricular ejection fraction improved and end-systolic volume index decreased in all subjects; there was no evidence of ongoing active myocardial injury by CMR (edema) or hs-cTnI; and  there were no interim symptoms, impaired activity tolerance, or hospitalizations. At the time of the report there was no evidence of myocardial dysfunction or ongoing myocardial injury at intermediate-term follow-up and no subsequent adverse cardiac events. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.