Precordial pain/chest pain/possible myocarditis/pericarditis; Fatigue; This spontaneous case was reported by a consumer and describes the occurrence of CHEST PAIN (Precordial pain/chest pain/possible myocarditis/pericarditis) and FATIGUE (Fatigue) in a 23-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 066H21A) for COVID-19 vaccination.     Concurrent medical conditions included Sulfonamide allergy (Allergy to sulfonamide medications.).    On 12-Jan-2022, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) .25 milliliter once. On 19-Jan-2022, the patient experienced CHEST PAIN (Precordial pain/chest pain/possible myocarditis/pericarditis) (seriousness criterion hospitalization) and FATIGUE (Fatigue) (seriousness criterion hospitalization). The patient was treated with KETOROLAC TROMETHAMINE (TORADOL) (intravenous) for Adverse event, at an unspecified dose and frequency. At the time of the report, CHEST PAIN (Precordial pain/chest pain/possible myocarditis/pericarditis) and FATIGUE (Fatigue) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood test: abnormal (abnormal) possible myocarditis/pericarditis. On an unknown date, C-reactive protein: result not provided RESULT NOT PROVIDED. On an unknown date, Differential white blood cell count: result not provided RESULT NOT PROVIDED. On an unknown date, Echocardiogram: abnormal (abnormal) possible myocarditis/pericarditis. On an unknown date, Electrocardiogram: abnormal (abnormal) possible myocarditis/pericarditis. On an unknown date, Full blood count: result not provided RESULT NOT PROVIDED. On an unknown date, Metabolic function test: result not provided RESULT NOT PROVIDED. On an unknown date, N-terminal prohormone brain natriuretic peptide: result not provided RESULT NOT PROVIDED. On an unknown date, Red blood cell sedimentation rate: result not provided RESULT NOT PROVIDED. On an unknown date, Respiratory viral panel: result not provided RESULT NOT PROVIDED. On an unknown date, Troponin: abnormal (abnormal) above the normal expected range. On an unknown date, Troponin T: result not provided RESULT NOT PROVIDED and result not provided RESULT NOT PROVIDED.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered CHEST PAIN (Precordial pain/chest pain/possible myocarditis/pericarditis) and FATIGUE (Fatigue) to be related.    No concomitant medication was provided. It was reported that the patient was administered to the emergency department for chest pain. The tests performed were EKG, echocardiogram and multiple blood tests which indicated possible myocarditis/pericarditis. Troponin levels were above the normal expected range. The patient was given Toradol through intravenous (IV) while in the hospital.  Company Comment: This is a Spontaneous case concerning a 23-year-old male patient, with no relevant medical history, who experienced the unexpected and serious (hospitalization) events of Chest pain and Fatigue. The events occurred 1 week after the third dose of mRNA-1273 vaccine. Electrocardiogram, echocardiogram, and multiple blood tests were performed, and indicated possible myocarditis/pericarditis. Troponin levels were above the normal expected range. Treatment received was Toradol IV. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report.; Sender's Comments: This is a Spontaneous case concerning a 23-year-old male patient, with no relevant medical history, who experienced the unexpected and serious (hospitalization) events of Chest pain and Fatigue. The events occurred 1 week after the third dose of mRNA-1273 vaccine. Electrocardiogram, echocardiogram, and multiple blood tests were performed, and indicated possible myocarditis/pericarditis. Troponin levels were above the normal expected range. Treatment received was Toradol IV. The benefit-risk relationship of mRNA- 1273 vaccine is not affected by this report.