Inflammation of the heart muscle; Feels tired after walking couple of blocks; Feeling very very weak; This spontaneous case was reported by a consumer and describes the occurrence of MYOCARDITIS (Inflammation of the heart muscle) in a 72-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 027H21B, 002A21A and 002A21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Vegetarian.   On 26-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 26-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 06-Dec-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In July 2021, the patient experienced FATIGUE (Feels tired after walking couple of blocks) and ASTHENIA (Feeling very very weak). On an unknown date, the patient experienced MYOCARDITIS (Inflammation of the heart muscle) (seriousness criterion medically significant). At the time of the report, MYOCARDITIS (Inflammation of the heart muscle) outcome was unknown and FATIGUE (Feels tired after walking couple of blocks) and ASTHENIA (Feeling very very weak) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In February 2022, Computerised tomogram: normal (normal) CT scan performed 2 weeks ago which came out to be normal.. On an unknown date, Cardiac stress test: normal (normal) Normal.         The reporter stated since July patient got his heart checkup and looks like he had a side effect from the vaccine. The patient was feeling very weak and tired after walking couple of blocks. The reporter stated that before receiving the booster vaccine patient, started feeling tired. Reporter stated that they believe it maybe heart problem or heart pumping hence patient received a check-up by their doctor.  The doctor did stress test that came out to be normal. CT scan performed 2 weeks ago which came out to be normal. There was no issue with the patient's heart and heart was pumping normal.   Patient was very athletics guy.   The reporter again describes, the patient eats well, sleep wells, follows vegetarian diet. There was no treatment at the moment. Patient was described as person who eats well, sleep wells and follows vegetarian diet. Reporter stated that this might be a side effect from the 2nd shot of the vaccine. No concomitant medication details provided. No treatment medication information was provided.  Company Comment: This spontaneous case concerns a 72-year-old, male patient with no medical history reported, who experienced the expected, serious (Seriousness criterion Medically Significant), AESI of Myocarditis an unknown duration after the third dose of mRNA-1273. No relevant lab data or details regarding clinical course and treatment received were reported. At the time of report, outcome of the event was Unknown. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 04-Mar-2022: Follow-up included start dates, route of administration, anatomical location and Lot numbers of Moderna vaccine were updated.; Sender's Comments: This spontaneous case concerns a 72-year-old, male patient with no medical history reported, who experienced the expected, serious (Seriousness criterion Medically Significant), AESI of Myocarditis an unknown duration after the third dose of mRNA-1273. No relevant lab data or details regarding clinical course and treatment received were reported. At the time of report, outcome of the event was Unknown. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.