Chronic Inflammatory Demyelinating Polyneuropathy; Could not communicate but she could hear people talking during her episode (more severe); She went from 50% strength down to 20%; Had complete leg failure; Muscle weakness  (more severe); Stiffness  (more severe); Joint pain  (more severe); Loss of her motor skills (more severe); She couldn't use her hands (more severe); Experienced myoclonus (more severe); Seizure episodes (more severe); Lost control of her arms and legs (more severe); Her head went back and forth (more severe); Loss of speech (more severe); This spontaneous case was reported by a consumer and describes the occurrence of MUSCULAR WEAKNESS (Muscle weakness  (more severe)), MUSCULOSKELETAL STIFFNESS (Stiffness  (more severe)), ARTHRALGIA (Joint pain  (more severe)), MOTOR DYSFUNCTION (Loss of her motor skills (more severe)), MUSCULAR WEAKNESS (She couldn't use her hands (more severe)), MYOCLONUS (Experienced myoclonus (more severe)), SEIZURE (Seizure episodes (more severe)), LOSS OF CONTROL OF LEGS (Lost control of her arms and legs (more severe)), HEAD DISCOMFORT (Her head went back and forth (more severe)), DYSPRAXIA (Loss of speech (more severe)), SPEECH DISORDER (Could not communicate but she could hear people talking during her episode (more severe)), ASTHENIA (She went from 50% strength down to 20%), MONOPLEGIA (Had complete leg failure) and CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (Chronic Inflammatory Demyelinating Polyneuropathy) in a 47-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 039B21A and 025C21A) for COVID-19 vaccination.     No Medical History information was reported.   On 14-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 12-May-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 21-May-2021, the patient experienced MUSCULAR WEAKNESS (Muscle weakness  (more severe)) (seriousness criterion hospitalization), MUSCULOSKELETAL STIFFNESS (Stiffness  (more severe)) (seriousness criterion hospitalization), ARTHRALGIA (Joint pain  (more severe)) (seriousness criterion hospitalization), MOTOR DYSFUNCTION (Loss of her motor skills (more severe)) (seriousness criterion hospitalization), MUSCULAR WEAKNESS (She couldn't use her hands (more severe)) (seriousness criterion hospitalization), MYOCLONUS (Experienced myoclonus (more severe)) (seriousness criterion hospitalization), SEIZURE (Seizure episodes (more severe)) (seriousness criteria hospitalization and medically significant), LOSS OF CONTROL OF LEGS (Lost control of her arms and legs (more severe)) (seriousness criteria hospitalization and medically significant), HEAD DISCOMFORT (Her head went back and forth (more severe)) (seriousness criterion hospitalization), DYSPRAXIA (Loss of speech (more severe)) (seriousness criterion hospitalization), ASTHENIA (She went from 50% strength down to 20%) (seriousness criterion hospitalization) and MONOPLEGIA (Had complete leg failure) (seriousness criteria hospitalization and medically significant). On 25-May-2021, the patient experienced SPEECH DISORDER (Could not communicate but she could hear people talking during her episode (more severe)) (seriousness criterion hospitalization). On an unknown date, the patient experienced CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (Chronic Inflammatory Demyelinating Polyneuropathy) (seriousness criteria hospitalization and medically significant). The patient was hospitalized from 25-May-2021 to 29-May-2021 due to ARTHRALGIA, ASTHENIA, DYSPRAXIA, HEAD DISCOMFORT, LOSS OF CONTROL OF LEGS, MONOPLEGIA, MOTOR DYSFUNCTION, MUSCULAR WEAKNESS, MUSCULAR WEAKNESS, MUSCULOSKELETAL STIFFNESS, MYOCLONUS, SEIZURE and SPEECH DISORDER. At the time of the report, MUSCULAR WEAKNESS (Muscle weakness  (more severe)), MUSCULOSKELETAL STIFFNESS (Stiffness  (more severe)), ARTHRALGIA (Joint pain  (more severe)), MOTOR DYSFUNCTION (Loss of her motor skills (more severe)), MUSCULAR WEAKNESS (She couldn't use her hands (more severe)), MYOCLONUS (Experienced myoclonus (more severe)), SEIZURE (Seizure episodes (more severe)), LOSS OF CONTROL OF LEGS (Lost control of her arms and legs (more severe)), HEAD DISCOMFORT (Her head went back and forth (more severe)), DYSPRAXIA (Loss of speech (more severe)), SPEECH DISORDER (Could not communicate but she could hear people talking during her episode (more severe)), ASTHENIA (She went from 50% strength down to 20%), MONOPLEGIA (Had complete leg failure) and CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (Chronic Inflammatory Demyelinating Polyneuropathy) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 09-Dec-2020, SARS-CoV-2 test: positi ve (Positive) Patient was tested positive for COVID-19. On an unknown date, Computerised tomogram: normal. On an unknown date, Electromyogram: (abnormal) Neurologist gave patient EMG Test and she was diagnosed with Chronic Inflammatory Demyelinating Polyneuropathy - an autoimmune response caused by vaccines. On an unknown date, Ultrasound Doppler: normal. On an unknown date, X-ray: normal.         Concomitant information was not provided. Treatment information was not provided. Patient was diagnosed with  Chronic Inflammatory Demyelinating Polyneuropathy - an autoimmune response caused by vaccines)   .  Patient was not pregnant.  Company comment: 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. However, more information is required for further assessment.   This case was linked to MOD-2021-293170 (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. However, more information is required for further assessment.