Guillain Barre Syndrome which progressed to CIDP; Could not stand up or walk alone; Not able to walk.; dizzy; Fell constantly; broke her ankle; fell at home and broke it again another place; been in a wheelchair; fell at home and broke it again another place; This spontaneous case was reported by a patient and describes the occurrence of CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (Guillain Barre Syndrome which progressed to CIDP) in a 46-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 062E21A and 059E21A) for COVID-19 prophylaxis. The occurrence of additional non-serious events is detailed below.     Previously administered products included for Product used for unknown indication: Flu shot (a year before). Past adverse reactions to the above products included No adverse event with Flu shot. Concurrent medical conditions included Drug allergy, Adhesive tape allergy, Fibromyalgia worsened (started when she was in Junior High, got worse recently), Guillain Barre syndrome, Drug allergy, Drug allergy, Drug allergy and Allergy to chemicals. Concomitant products included ERENUMAB (AIMOVIG [ERENUMAB]), ALENDRONATE SODIUM (ALENDRONATE), ATORVASTATIN, BACLOFEN, BUPRENORPHINE HYDROCHLORIDE (BELBUCA), SUVOREXANT (BELSOMRA) and CALCIUM CITRATE for an unknown indication.   On 12-Aug-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 09-Sep-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient experienced CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (Guillain Barre Syndrome which progressed to CIDP) (seriousness criterion medically significant), DYSSTASIA (Could not stand up or walk alone), GAIT DISTURBANCE (Not able to walk.), DIZZINESS (dizzy), FALL (Fell constantly), ANKLE FRACTURE (broke her ankle), FALL (fell at home and broke it again another place), WHEELCHAIR USER (been in a wheelchair) and FRACTURE (fell at home and broke it again another place). At the time of the report, CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (Guillain Barre Syndrome which progressed to CIDP), DYSSTASIA (Could not stand up or walk alone), GAIT DISTURBANCE (Not able to walk.), DIZZINESS (dizzy), FALL (Fell constantly), ANKLE FRACTURE (broke her ankle), FALL (fell at home and broke it again another place), WHEELCHAIR USER (been in a wheelchair) and FRACTURE (fell at home and broke it again another place) had not resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Haematocrit: levels was at 3 levels was at 3. On an unknown date, Red blood cell count: drop down really low drop down really low.         Reporter stated that after she got her shot, it started after she got the first shot and got super bad after the second one. She developed Guillain Barre, and it progressed to CIDP. Because it lasted longer than 8 weeks. She was now confined to a wheelchair.  Patient received stated she got one of the vaccines in the left and one in right IM. Patient was taking medications. Patient's HCP is aware of patient condition.  Patient stated her red blood cell drop down really low. Her hematocrit levels were at 3. Could not stand up or walk alone. She was dizzy. She fell constantly. Her husband had to carry her to the bathroom. She fell when she went to the emergency and broke her ankle. She fell at home and broke it again another place. patient does not experience a similar event in the past. Patient was not able to walk, she been in a wheelchair since then. Patient had mentioned that the symptoms got worsened. No treatment information was provided. Company comment: This spontaneous case concerns a 46-year-old female patient, with medical history of Guillain Barre syndrome, who experienced the serious (due to medically significant) unexpected AESI of CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (among other non-serious adverse events) after the second dose of mRNA-1273 vaccine. The event was reported with no onset date; hence, exact latency cannot be assessed. The narrative of the source document states that Guillain Barre syndrome progressed to chronic inflammatory demyelinating polyradiculoneuropathy, and she could not stand up or walk alone, she fell constantly and had fractured. The medical history remains as a confounder for the event. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.   This case was linked to MOD-2022-591121.   Most recent FOLLOW-UP information incorporated above includes: On 17-Jun-2022: Added reporter information, patient demographics, concomitant medications, vaccine dosage detail, allergies and events.; Sender's Comments: This spontaneous case concerns a 46-year-old female patient, with medical history of Guillain Barre syndrome, who experienced the serious (due to medically significant) unexpected AESI of CHRONIC INFLAMMATORY DEMYELINATING POLYRADICULONEUROPATHY (among other non-serious adverse events) after the second dose of mRNA-1273 vaccine. The event was reported with no onset date; hence, exact latency cannot be assessed. The narrative of the source document states that Guillain Barre syndrome progressed to chronic inflammatory demyelinating polyradiculoneuropathy, and she could not stand up or walk alone, she fell constantly and had fractured. The medical history remains as a confounder for the event. The benefit-risk relationship of the mRNA-1273 vaccine is not affected by this report.