could be MS (Multiple Sclerosis); diagnosed with Guillain-Barre Syndrome; hands were tingling; Can't determine if water is hot or cold; numbness; Started getting worse with her motor skills and everything; She has two lesions in her brain; Legs to torso area is very heavy; This spontaneous case was reported by a consumer (subsequently medically confirmed) and describes the occurrence of GUILLAIN-BARRE SYNDROME (diagnosed with Guillain-Barre Syndrome), MULTIPLE SCLEROSIS (could be MS (Multiple Sclerosis)), HYPOAESTHESIA (numbness), PARAESTHESIA (hands were tingling), SENSORY LOSS (Can't determine if water is hot or cold), LIMB DISCOMFORT (Legs to torso area is very heavy), MOTOR DYSFUNCTION (Started getting worse with her motor skills and everything) and CENTRAL NERVOUS SYSTEM LESION (She has two lesions in her brain) in a 51-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 036B21A and 006B21A) for COVID-19 vaccination.     Concurrent medical conditions included Overweight.   On 27-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 20-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 15-Apr-2021, the patient experienced HYPOAESTHESIA (numbness) (seriousness criterion hospitalization prolonged). On 26-Apr-2021, the patient experienced PARAESTHESIA (hands were tingling) (seriousness criterion hospitalization), SENSORY LOSS (Can't determine if water is hot or cold) (seriousness criterion hospitalization prolonged) and LIMB DISCOMFORT (Legs to torso area is very heavy) (seriousness criterion hospitalization prolonged). On 05-May-2021, the patient experienced GUILLAIN-BARRE SYNDROME (diagnosed with Guillain-Barre Syndrome) (seriousness criteria hospitalization prolonged and medically significant) and CENTRAL NERVOUS SYSTEM LESION (She has two lesions in her brain) (seriousness criterion hospitalization prolonged). On 12-May-2021, the patient experienced MULTIPLE SCLEROSIS (could be MS (Multiple Sclerosis)) (seriousness criteria hospitalization and medically significant). On an unknown date, the patient experienced MOTOR DYSFUNCTION (Started getting worse with her motor skills and everything) (seriousness criterion hospitalization prolonged). The patient was hospitalized on 05-May-2021 due to CENTRAL NERVOUS SYSTEM LESION, GUILLAIN-BARRE SYNDROME, HYPOAESTHESIA, LIMB DISCOMFORT, MOTOR DYSFUNCTION, PARAESTHESIA and SENSORY LOSS. At the time of the report, GUILLAIN-BARRE SYNDROME (diagnosed with Guillain-Barre Syndrome), MULTIPLE SCLEROSIS (could be MS (Multiple Sclerosis)), HYPOAESTHESIA (numbness), PARAESTHESIA (hands were tingling), SENSORY LOSS (Can't determine if water is hot or cold), LIMB DISCOMFORT (Legs to torso area is very heavy), MOTOR DYSFUNCTION (Started getting worse with her motor skills and everything) and CENTRAL NERVOUS SYSTEM LESION (She has two lesions in her brain) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 12-May-2021, Magnetic resonance imaging: abnormal (abnormal) The neurologist told her she has two lesions in her brain and one on her neck, they said it could be MS (Multiple Sclerosis)..         Concomitant product use was not provided by the reporter.   Treatment medication included IVIG medication. She was given a 3-day unknown medication to shrink the brain lesions.  Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   This case was linked to MOD-2021-127948 (Patient Link).; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.