inflammation in the heart muscles; burning in the heart and muscles /experienced a burning in the stomach,inside the left arm, shoulder, goes to the back.; Blood pressure is going up and down; also has pain in the belly; experiencing heart issues; needs to go to the bathroom all the time; didn't feel like herself; When she exerts herself, like to walk, she has shortness of breath; discomfort in the waist going back; burning in the heart and muscles; mild temperature; This spontaneous case was reported by a consumer and describes the occurrence of MYOCARDITIS (inflammation in the heart muscles) in a 54-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 20-Oct-2021, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 21-Oct-2021, the patient experienced MYOCARDITIS (inflammation in the heart muscles) (seriousness criteria hospitalization and medically significant), BURNING SENSATION (burning in the heart and muscles /experienced a burning in the stomach,inside the left arm, shoulder, goes to the back.), BLOOD PRESSURE FLUCTUATION (Blood pressure is going up and down), ABDOMINAL PAIN (also has pain in the belly), CARDIAC DISORDER (experiencing heart issues), POLLAKIURIA (needs to go to the bathroom all the time), FEELING ABNORMAL (didn't feel like herself), DYSPNOEA (When she exerts herself, like to walk, she has shortness of breath), DISCOMFORT (discomfort in the waist going back), MYALGIA (burning in the heart and muscles) and PYREXIA (mild temperature). The patient was treated with IBUPROFEN for Burning sensation, at an unspecified dose and frequency. At the time of the report, MYOCARDITIS (inflammation in the heart muscles), ABDOMINAL PAIN (also has pain in the belly), CARDIAC DISORDER (experiencing heart issues), POLLAKIURIA (needs to go to the bathroom all the time), FEELING ABNORMAL (didn't feel like herself), DYSPNOEA (When she exerts herself, like to walk, she has shortness of breath), DISCOMFORT (discomfort in the waist going back) and PYREXIA (mild temperature) outcome was unknown and BURNING SENSATION (burning in the heart and muscles /experienced a burning in the stomach,inside the left arm, shoulder, goes to the back.), BLOOD PRESSURE FLUCTUATION (Blood pressure is going up and down) and MYALGIA (burning in the heart and muscles) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Blood cholesterol: 140 to 230 (High) High(140 to 230 something) and normal (normal) Normal. On an unknown date, Blood pressure measurement: abnormal (abnormal) abnormal(blood pressure is up and down). On an unknown date, Blood triglycerides: abnormal (abnormal) abnormal(borderline to be consider diabetic) and normal (normal) Normal. On an unknown date, Body temperature: 104 (High) High. On an unknown date, Chest scan: abnormal (abnormal) There was inflammation in the heart muscles, but it seems that she didn't have a heart attack.. On an unknown date, Heart rate irregular: abnormal (abnormal) heart rhythm is not regular.         No concomitant medication information was provided. Laboratory data was mentioned as patient did EKG and blood work at the emergency room but results was not given. On 14-Nov-2021 in hospital patient took the tests for ECG, cardiac test,cardiac enzymes but results was not given.  Company Comment: The case concerns a 54-year-old-female patient with no previous relevant medical history, who experienced the serious, expected, AESI event of myocarditis. The event started one day after the second dose of mRNA-1273 Vaccine. The patient was admitted to hospital; however, discharge summary has not been disclosed.  The rechallenge was not applicable since the events have not been reported after the first dose. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.    This case was linked to MOD-2021-380274 (Patient Link).   Most recent FOLLOW-UP information incorporated above includes: On 10-Nov-2021: Significant Follow Up Appended contains events added. On 16-Nov-2021: Follow up contains significant information as case upgrade to serious due to hospitalization for the heart inflammation, addition of new events, lab data and treatment medication.; Sender's Comments: The case concerns a 54-year-old-female patient with no previous relevant medical history, who experienced the serious, expected, AESI event of myocarditis. The event started one day after the second dose of mRNA-1273 Vaccine. The patient was admitted to hospital; however, discharge summary has not been disclosed.  The rechallenge was not applicable since the events have not been reported after the first dose. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.