High fever of 105° F; It "almost killed him"; Lost his appetite; Couldn't sleep; Sweating a lot; Hard for him to breath/difficulty breathing; "It was very painful"; Muscle ache that targeted the weakest muscles of his body (arm, neck, and lower back); Headaches; This spontaneous case was reported by a consumer and describes the occurrence of HYPERPYREXIA (High fever of 105° F) in a 29-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 052E21A and 020F21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included COVID-19, Pneumonia and Dizziness.   On 31-Aug-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 28-Sep-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 31-Aug-2021, the patient experienced HYPERPYREXIA (High fever of 105° F) (seriousness criterion medically significant), VACCINATION COMPLICATION (It "almost killed him"), DECREASED APPETITE (Lost his appetite), INSOMNIA (Couldn't sleep), HYPERHIDROSIS (Sweating a lot), DYSPNOEA (Hard for him to breath/difficulty breathing), PAIN ("It was very painful"), MYALGIA (Muscle ache that targeted the weakest muscles of his body (arm, neck, and lower back)) and HEADACHE (Headaches). The patient was treated with PARACETAMOL (TYLENOL) for Adverse event, at an unspecified dose and frequency. On 02-Sep-2021, HYPERPYREXIA (High fever of 105° F) had resolved. At the time of the report, VACCINATION COMPLICATION (It "almost killed him"), DECREASED APPETITE (Lost his appetite), INSOMNIA (Couldn't sleep), HYPERHIDROSIS (Sweating a lot), DYSPNOEA (Hard for him to breath/difficulty breathing), PAIN ("It was very painful"), MYALGIA (Muscle ache that targeted the weakest muscles of his body (arm, neck, and lower back)) and HEADACHE (Headaches) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 31-Aug-2021, Body temperature: 105° f (High) 105° F.  mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) and mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) dosing remained unchanged.  Concomitant medication was not provided.  Company Comment - This case concerns a 29-year-old male patient with medical history of COVID-19, pneumonia and dizziness, who experienced unexpected serious event of hyperpyrexia. The event occurred on the same day after the first dose of mRNA-1273 (Moderna COVID-19 Vaccine) administration. The rechallenge was unknown as details about the second dose was not disclosed. Causality for the reported events were not provided by the reporter. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) in not affected by this report. Event assessed as serious per Regulatory Authority reporting as event was considered medically significant and is an important medical event.   This case was linked to MOD-2021-335730 (Patient Link).; Sender's Comments: This case concerns a 29-year-old male patient with medical history of COVID-19, pneumonia and dizziness, who experienced unexpected serious event of hyperpyrexia. The event occurred on the same day after the first dose of mRNA-1273 (Moderna COVID-19 Vaccine) administration. The rechallenge was unknown as details about the second dose was not disclosed. Causality for the reported events were not provided by the reporter. The benefit-risk relationship of mRNA-1273 (Moderna COVID-19 Vaccine) in not affected by this report. Event assessed as serious per Regulatory Authority reporting as event was considered medically significant and is an important medical event.