Myocarditis; Substernal chest pain; Symptoms worsened; Deep inspiration; Fever; Chills; body aches; This literature-non-study case was reported in a literature article and describes the occurrence of MYOCARDITIS (Myocarditis), CHEST PAIN (Substernal chest pain), CONDITION AGGRAVATED (Symptoms worsened), DYSPNOEA (Deep inspiration) and PYREXIA (Fever) in a 24-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.   LITERATURE REFERENCE: DS.. Myocarditis following COVID-19 vaccination. Case Rep. 2021;16:2142-45     No Medical History information was reported.   On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient experienced MYOCARDITIS (Myocarditis) (seriousness criteria hospitalization and medically significant), CHEST PAIN (Substernal chest pain) (seriousness criterion hospitalization), CONDITION AGGRAVATED (Symptoms worsened) (seriousness criterion hospitalization), DYSPNOEA (Deep inspiration) (seriousness criterion hospitalization), PYREXIA (Fever) (seriousness criterion hospitalization), CHILLS (Chills) and MYALGIA (body aches). The patient was hospitalized from sometime in 2021 to sometime in 2021 due to CHEST PAIN, CONDITION AGGRAVATED, DYSPNOEA and MYOCARDITIS. At the time of the report, MYOCARDITIS (Myocarditis), CHEST PAIN (Substernal chest pain), CONDITION AGGRAVATED (Symptoms worsened), DYSPNOEA (Deep inspiration), PYREXIA (Fever), CHILLS (Chills) and MYALGIA (body aches) was resolving.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Blood creatine phosphokinase (49-348): 704 (High) U/L. In 2021, C-reactive protein: 26.4 (High) mg/L. In 2021, Computerised tomogram: abnormal calcium score of 0 without coronary artery stenosis and small bilateral pleural effusions.. In 2021, Echocardiogram: normal normal. In 2021, Ejection fraction: 65 LVEF was 65%. No focal wall motion abnormality was seen. In 2021, Electrocardiogram: abnormal sinus rhythm without ischemic changes. The left ventricular ejection fraction (LVEF) was 65%. No focal wall motion abnormality was seen.. In 2021, Magnetic resonance imaging: abnormal normal LV size and EF (58%), patchy midmyocardial and epicardial delayed gadolinium enhancement, with superimposed edema. In 2021, SARS-CoV-2 test: negative negative. In 2021, Serology test: negative negative (parvovirus B19, Ebstein-Barr virus, adenovirus, influenza, herpes simplex virus 1 and 2 and Lyme antibody were all negative). In 2021, Troponin (0.01-0.04): 18.94 (High) ng/mL.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered MYOCARDITIS (Myocarditis) and CHEST PAIN (Substernal chest pain) to be possibly related. No further causality assessments were provided for CONDITION AGGRAVATED (Symptoms worsened), DYSPNOEA (Deep inspiration), PYREXIA (Fever), CHILLS (Chills) and MYALGIA (body aches).    Concomitant medication not provided. Treatment medication included betablocker medication. Patient was instructed to avoid strenuous activities for three months, as well as non-steroidal anti-inflammatory drugs (NSAIDs).  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   This case was linked to MOD-2021-223827 (Patient Link).; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.