Strokes; Blood clots; Myocarditis were diagnosed; Pericarditis were diagnosed; Heart blocks; Started with arrithmias 5 days after; Felt sick like flu 2 days after; This spontaneous case was reported by a consumer and describes the occurrence of ARRHYTHMIA (Started with arrithmias 5 days after), CEREBROVASCULAR ACCIDENT (Strokes), THROMBOSIS (Blood clots), MYOCARDITIS (Myocarditis were diagnosed) and PERICARDITIS (Pericarditis were diagnosed) in a 43-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 020F21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.    On 26-Aug-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 28-Aug-2021, the patient experienced INFLUENZA LIKE ILLNESS (Felt sick like flu 2 days after). On 31-Aug-2021, the patient experienced ARRHYTHMIA (Started with arrithmias 5 days after) (seriousness criterion medically significant). On an unknown date, the patient experienced CEREBROVASCULAR ACCIDENT (Strokes) (seriousness criterion medically significant), THROMBOSIS (Blood clots) (seriousness criterion medically significant), MYOCARDITIS (Myocarditis were diagnosed) (seriousness criterion medically significant), PERICARDITIS (Pericarditis were diagnosed) (seriousness criterion medically significant) and ATRIOVENTRICULAR BLOCK (Heart blocks). At the time of the report, ARRHYTHMIA (Started with arrithmias 5 days after), CEREBROVASCULAR ACCIDENT (Strokes), THROMBOSIS (Blood clots), MYOCARDITIS (Myocarditis were diagnosed), PERICARDITIS (Pericarditis were diagnosed), ATRIOVENTRICULAR BLOCK (Heart blocks) and INFLUENZA LIKE ILLNESS (Felt sick like flu 2 days after) outcome was unknown.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was unknown.       No concomitant medication were reported. Treatment medication included Beta-blockers.  The patient used a heart monitor for 3 weeks.  Company comment: This case concerns a 43 year-old female patient with no reported medical history, who experienced the expected serious events of Myocarditis (AESI) and Pericarditis (AESI) and the unexpected serious events of Cerebrovascular accident (AESI), Arrhythmia (AESI), and Thrombosis. The event of Arrhythmia occurred 5 days after the first dose of mRNA-1273 vaccine and the other events occurred an unknown number of days after the first dose. Details of clinical presentation, diagnostic criteria, and clinical course for the events were not provided.  The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This case concerns a 43 year-old female patient with no reported medical history, who experienced the expected serious events of Myocarditis (AESI) and Pericarditis (AESI) and the unexpected serious events of Cerebrovascular accident (AESI), Arrhythmia (AESI), and Thrombosis. The event of Arrhythmia occurred 5 days after the first dose of mRNA-1273 vaccine and the other events occurred an unknown number of days after the first dose. Details of clinical presentation, diagnostic criteria, and clinical course for the events were not provided.  The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.