patient was diagnosed with guillain barre syndrome; he has demyelination of his nerves, and they are not functioning the right way; he has fallen 4 times; he is very shaky, and if he does not grab onto something,he will fall; Initial information received on 21-Mar-2023 regarding an unsolicited valid legal serious case received from a consumer/non-hcp (Non-healthcare professional).  This case involves a 79 years old male patient and patient was diagnosed with guillain barre syndrome, he has demyelination of his nerves, and they are not functioning the right way, fallen 4 times and he is very shaky, and if he does not grab onto something,he will fall after receiving  Influenza Quadrival A-B Vaccine [Fluzone Quadrivalent].  The patient's past medical history, medical treatment(s), concomitant medication(s), vaccination(s) and family history were not provided.   On an unknown date in October 2021, the patient received an unknown dose of suspect Influenza Quadrival A-B Vaccine Suspension for injection (Strength-standard) (with an unknown expiry date and lot number via unknown route in unknown administration site for Immunization.  On an unknown date, the patient developed an event of patient was diagnosed with guillain barre syndrome (guillain-barre syndrome), he has demyelination of his nerves, and they are not functioning the right way (demyelination), he has fallen 4 times (fall) and he is very shaky, and if he does not grab onto something,he will fall (tremor) (latency: unknown) following the administration of Influenza Quadrival A-B Vaccine.   Relevant laboratory test results included: Lumbar puncture - On an unknown date:  [diagnosed with GBS]  It was reported, The patient is seeking legal action; patient states, "there has to be monetary value to my life, this has taken over my whole body." The patient notes that he does not currently have legal representation; states that no one wants to take his case. The patient states that he tried to represent himself, but he just received an email on the 17th that his case is going to a completely different judge. The patient reports that when he was first hospitalized, they did a spinal tap and told him that he had GBS, and through process of elimination, it was most likely caused by the FLUZONE QUADRIVALENT shot. The patient reports that GBS is very debilitating; states that before he received FLUZONE QUADRIVALENT, he was "very vital"; reports that now, after the shot, he is "next thing to a wheelchair." The patient reports that he has demyelination of his nerves, and they are not functioning the right way. He states that he is very shaky, and if he does not grab onto something, he will fall. The patient notes that he has been hospitalized over 5 times, and that he has fallen 4 times. The patient reports that he goes to sleep at night crying because he was so vital before the shot, and the shot has turned everything upside down; states that had he known what would happen, he never would have gotten the FLUZONE QUADRIVALENT shot. The patient also reports that he is receiving IVIG to slow down the demyelination from the flu shot. The patient notes that if his HCP is contacted, all of the paperwork can be retrieved that shows his history of GBS.  Action taken: not applicable.  It was not reported if the patient received a corrective treatment for the reported events except for demyelination for which he received IVIG (Intravenous Immunoglobulin).  At time of reporting, the outcome was Not Recovered / Not Resolved for the reported events  Seriousness criteria: Medically significant for guillain-barre syndrome and demyelination and hospitalization for all the reported events.; Sender's Comments: Sanofi company comment dated 23-Mar -2023: This case involves a 79 years old male patient and patient was diagnosed with guillain barre syndrome, he has demyelination of his nerves, and they are not functioning the right way, fallen 4 times and he is very shaky, and if he does not grab onto something,he will fall after receiving  Influenza Quadrival A-B Vaccine [Fluzone Quadrivalent]. Furthermore, information regarding condition at the time of vaccination excluding other predisposing etiologies would be needed for complete assessment of the case. Based upon the reported information, the role of the suspect vaccine cannot be assessed.