insomnia; shortness of breath; Arm pains which come and go/leg pain; back pain; chest pain; fatigue; Headaches; I came down with Chest Pain. I went to the Emergency Room for the Chest Pain where I was diagnosed with Pericarditis / Stabbing Chest pain on the left side; Heart Palpitations; Shortness of breath when I lie down; This spontaneous case was reported by a consumer and describes the occurrence of PERICARDITIS (I came down with Chest Pain. I went to the Emergency Room for the Chest Pain where I was diagnosed with Pericarditis / Stabbing Chest pain on the left side) in a 21-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 023C21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concomitant products included IBUPROFEN for an unknown indication.    On 24-May-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 27-May-2021, the patient experienced PERICARDITIS (I came down with Chest Pain. I went to the Emergency Room for the Chest Pain where I was diagnosed with Pericarditis / Stabbing Chest pain on the left side) (seriousness criterion medically significant), PALPITATIONS (Heart Palpitations) and ORTHOPNOEA (Shortness of breath when I lie down). On an unknown date, the patient experienced INSOMNIA (insomnia), DYSPNOEA (shortness of breath), PAIN IN EXTREMITY (Arm pains which come and go/leg pain), BACK PAIN (back pain), CHEST PAIN (chest pain), FATIGUE (fatigue) and HEADACHE (Headaches). The patient was treated with IBUPROFEN for Adverse event, at an unspecified dose and frequency. At the time of the report, PERICARDITIS (I came down with Chest Pain. I went to the Emergency Room for the Chest Pain where I was diagnosed with Pericarditis / Stabbing Chest pain on the left side), INSOMNIA (insomnia), DYSPNOEA (shortness of breath), PAIN IN EXTREMITY (Arm pains which come and go/leg pain), BACK PAIN (back pain), PALPITATIONS (Heart Palpitations), ORTHOPNOEA (Shortness of breath when I lie down), CHEST PAIN (chest pain), FATIGUE (fatigue) and HEADACHE (Headaches) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 27-May-2021, Heart rate: high (High) Elevated Heart Rate. On an unknown date, Electrocardiogram: abnormal (abnormal) diagnosed with Pericarditis. On an unknown date, Ultrasound Doppler: abnormal (abnormal) diagnosed with Pericarditis.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   Patient went to the Emergency Room for the Chest Pain where he was diagnosed with Pericarditis.The patient has made 2 trips to the Emergency Room for chest pain. 2Jun2021 and 2AUG2021 were the dated of the Emergency Room visits.  Patient provides consent for Safety to contact him either via telephone or e-mail. Patients Primary Care physician, Cardiologists, and vaccination provider are listed as contacts in the case. Permission granted for Safety to contact them.  Company Comment: This case concerns a 21-year-old male patient with no reported relevant medical history but was on concomitant use of Ibuprofen for unknown indication, who experienced the unexpected event of Pericarditis. The event occurred 3 days after the first dose of mRNA-1273 (Moderna COVID-19 Vaccine). The rechallenge not applicable as the report pertained to the first dose only. Causality assessment for the reported event was not provided by the reporter. The events are consistent with the current understanding of the mechanism of action of the vaccine. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report. Pericarditis is an adverse event of special interest.; Sender's Comments: This case concerns a 21-year-old male patient with no reported relevant medical history but was on concomitant use of Ibuprofen for unknown indication, who experienced the unexpected event of Pericarditis. The event occurred 3 days after the first dose of mRNA-1273 (Moderna COVID-19 Vaccine). The rechallenge not applicable as the report pertained to the first dose only. Causality assessment for the reported event was not provided by the reporter. The events are consistent with the current understanding of the mechanism of action of the vaccine. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) is not affected by this report. Pericarditis is an adverse event of special interest.