Hyperreflexia; Very jumpy; Trouble drinking and swallowing medication; Abnormal gait; Fallen multiple times; Short term memory loss; Started experiencing more and more symptioms/started biting the inside of mouth; Overall fatigue; My right side seems weak; Brain Fog; Balance; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of HEMIPARESIS (My right side seems weak) in a 46-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 003C21A and 036B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Penicillin allergy, Sulfonamide allergy (Sulfa allergy), Slurred speech since 24-Apr-2021 and Dry mouth since 24-Apr-2021. Concomitant products included SERTRALINE from 2010 to an unknown date, LEVOTHYROXINE from 2015 to an unknown date and AMITRIPTYLINE from 2020 to an unknown date for an unknown indication.   On 20-Apr-2021 at 3:30 PM, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 17-May-2021 at 3:30 PM, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 27-May-2021, the patient experienced FEELING ABNORMAL (Brain Fog) and BALANCE DISORDER (Balance). On an unknown date, the patient experienced HEMIPARESIS (My right side seems weak) (seriousness criterion medically significant), HYPERREFLEXIA (Hyperreflexia), NERVOUSNESS (Very jumpy), DYSPHAGIA (Trouble drinking and swallowing medication), GAIT DISTURBANCE (Abnormal gait), FALL (Fallen multiple times), AMNESIA (Short term memory loss), MOUTH INJURY (Started experiencing more and more symptioms/started biting the inside of mouth) and FATIGUE (Overall fatigue). At the time of the report, HEMIPARESIS (My right side seems weak), HYPERREFLEXIA (Hyperreflexia), NERVOUSNESS (Very jumpy), DYSPHAGIA (Trouble drinking and swallowing medication), GAIT DISTURBANCE (Abnormal gait), FALL (Fallen multiple times), AMNESIA (Short term memory loss), MOUTH INJURY (Started experiencing more and more symptioms/started biting the inside of mouth) and FATIGUE (Overall fatigue) outcome was unknown and FEELING ABNORMAL (Brain Fog) and BALANCE DISORDER (Balance) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 16-Jun-2021, Computerised tomogram: normal (normal) Found nothing. On 29-Jun-2021, Blood test: normal (normal) Found nothing. On an unknown date, Magnetic resonance imaging head: normal (normal) Normal. On an unknown date, Magnetic resonance imaging neck: normal (normal) Normal.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   No treatment medication information provided.  Company Comment : This case concerns a 46-year-old, male patient with previous relevant medical history of use of concomitant medication sertraline, levothyroxine and amitriptyline, who experienced the unexpected event of hemiparesis. The events occurred on an unknown number of days after the second dose of mRNA-1273 Moderna vaccine. The rechallenge was not applicable since the events happened after the second dose. The medical history use of concomitant medication remains a confounder. The benefit-risk relationship of mRNA-1273 Moderna vaccine is not affected by this report.   This case was linked to MOD-2021-261591 (Patient Link).; Sender's Comments: This case concerns a 46-year-old, male patient with previous relevant medical history of use of concomitant medication sertraline, levothyroxine and amitriptyline, who experienced the unexpected event of hemiparesis. The events occurred on an unknown number of days after the second dose of mRNA-1273 Moderna vaccine. The rechallenge was not applicable since the events happened after the second dose. The medical history use of concomitant medication remains a confounder. The benefit-risk relationship of mRNA-1273 Moderna vaccine is not affected by this report.