Microscopic colitis; Premature ventricular contractions; Developed pericarditis after the booster shot; Gave another full dose, versus a half dose; This spontaneous case was reported by a patient and describes the occurrence of COLITIS MICROSCOPIC (Microscopic colitis), VENTRICULAR EXTRASYSTOLES (Premature ventricular contractions) and PERICARDITIS (Developed pericarditis after the booster shot) in a 57-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 989893, 036A21A and 013M20A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Allergy to antibiotic (Bactrim), Giant cell myocarditis (It was triggered by a virus.) since 2017 and Irritable bowel syndrome.   On 09-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 09-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 25-Aug-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 25-Aug-2021,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced OVERDOSE (Gave another full dose, versus a half dose). In September 2021, the patient experienced COLITIS MICROSCOPIC (Microscopic colitis) (seriousness criteria hospitalization and medically significant), VENTRICULAR EXTRASYSTOLES (Premature ventricular contractions) (seriousness criterion hospitalization) and PERICARDITIS (Developed pericarditis after the booster shot) (seriousness criteria hospitalization and medically significant). The patient was treated with BUDESONIDE at a dose of 3 capsules three times a day for week one and tapered down and IBUPROFEN at a dose of 800 milligram three times a day. At the time of the report, COLITIS MICROSCOPIC (Microscopic colitis) had not resolved, VENTRICULAR EXTRASYSTOLES (Premature ventricular contractions) and OVERDOSE (Gave another full dose, versus a half dose) outcome was unknown and PERICARDITIS (Developed pericarditis after the booster shot) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Echocardiogram: pericarditis Pericarditis. On an unknown date, Magnetic resonance imaging heart: pericarditis Pericarditis.         Concomitant medications include medications for heart to keep blood pressure at baseline. The patient developed pericarditis after the booster shot, began to have premature ventricle contractions, heart hurt upon exertion and was extremely fatigued. Cardiologist prescribed wearing an external heart  monitor device to monitor the heart activity and make a diagnosis. As patient continued to get worse an echocardiogram and subsequent cardiac MRI were performed and that procedure helped the doctors arrive at the diagnosis. Patient also reported that she was diagnosed with microscopic colitis, more immediately after the vaccine( around September 25th). She started having diarrhea and it got very severe and debilitating. She had been diagnosed with irritable bowel syndrome before but this was completely water, 15 times in the morning, leaking issues and explosive. They did testing at the doctors office and they gave her budesonide 3 capsules three times a day for week one and tapered down. It got better but now she was having a second occurrence of it. She was diagnosed with a cardiac MRI . There is pain when it beats and an increase of acute pain when laying down. Her shoulders hurt, it was not muscle related. Doctors said it was a likely a cause from the vaccination but were hesitant to say it. Doctors said they expected to see the reaction earlier. Other treatment drug reported included: might have given a shot of anti-inflammatory.  Company Comment: This spontaneous case reported by the patient concerning a 57-year-old female patient, with medical history of Giant Cell Myocarditis and Irritable bowel syndrome, who experienced the unexpected serious (due to medically significant and hospitalization), expected event of Pericarditis (AESI), the serious (due to medically significant and hospitalization), unexpected events of colitis microscopic and the serious (due to hospitalization) unexpected event of Ventricular extrasystoles (AESI) the month after receiving a third dose of mRNA-1273, which was considered an overdose since there is no evidence suggesting patient was immunocompromised. After vaccination she experienced premature ventricle contractions, her heart hurt upon exertion and she was extremely fatigued. Her cardiologist prescribed an external heart monitor to make a diagnosis. Since she got worse, an echocardiogram and subsequent cardiac MRI were performed, and diagnosis of pericarditis was made. She received ibuprofen as treatment and states that symptoms resolved after 3 months. She also experienced diarrhea that was severe and debilitating and was diagnosed with microscopic colitis. Budesonide was indicated. The event was resolving but she reports a second occurrence at the time of the report. The medical history of Giant Cell Myocarditis could be a confounder for the event pericarditis. The medical history of irritable bowel syndrome could be a confounder for the event colitis microscopic. The benefit-risk relationship of mRNA-1273 is not affected by this report.; Sender's Comments: This spontaneous case reported by the patient concerning a 57-year-old female patient, with medical history of Giant Cell Myocarditis and Irritable bowel syndrome, who experienced the unexpected serious (due to medically significant and hospitalization), expected event of Pericarditis (AESI), the serious (due to medically significant and hospitalization), unexpected events of colitis microscopic and the serious (due to hospitalization) unexpected event of Ventricular extrasystoles (AESI) the month after receiving a third dose of mRNA-1273, which was considered an overdose since there is no evidence suggesting patient was immunocompromised. After vaccination she experienced premature ventricle contractions, her heart hurt upon exertion and she was extremely fatigued. Her cardiologist prescribed an external heart monitor to make a diagnosis. Since she got worse, an echocardiogram and subsequent cardiac MRI were performed, and diagnosis of pericarditis was made. She received ibuprofen as treatment and states that symptoms resolved after 3 months. She also experienced diarrhea that was severe and debilitating and was diagnosed with microscopic colitis. Budesonide was indicated. The event was resolving but she reports a second occurrence at the time of the report. The medical history of Giant Cell Myocarditis could be a confounder for the event pericarditis. The medical history of irritable bowel syndrome could be a confounder for the event colitis microscopic. The benefit-risk relationship of mRNA-1273 is not affected by this report.