Guillain-Barre Syndrome; Guillain-Barre Syndrome; paresthesias of the right hemibody/weakness of the right hemibody; weakness that progressed to inability to feed himself and ultimately respiratory failure 48 hours later; weakness that progressed to inability to feed himself and ultimately respiratory failure 48 hours later; areflexia; encephalomalacia; weakness that progressed to inability to feed himself and ultimately respiratory failure 48 hours later; This case was reported in a literature article and described the occurrence of guillain barre syndrome in a adult male patient who received Flu unspecified (Influenza vaccine) for prophylaxis.   Co-suspect products included Flu unspecified (Influenza vaccine) (batch number UNK, expiry date unknown) for prophylaxis.   The patient's past medical history included stroke (cerebral arterystroke) and hemiplegia.   On an unknown date, the patient received Influenza vaccine and Influenza vaccine. On an unknown date, less than 2 months after receiving Influenza vaccine and not applicable after receiving Influenza vaccine, the patient experienced guillain barre syndrome (serious criteria hospitalization and GSK medically significant), guillain barre syndrome (serious criteria hospitalization and GSK medically significant), hemiparesthesia (serious criteria hospitalization and GSK medically significant), weakness (serious criteria hospitalization), feeding disorder (serious criteria hospitalization), respiratory failure (serious criteria hospitalization and GSK medically significant), encephalomalacia (serious criteria GSK medically significant) and areflexia (serious criteria hospitalization). The patient was treated with immunoglobulins nos (Intravenous Immunoglobulin), operations and procedures (Plasma Exchange) and operations and procedures (Plasma Exchange). Rechallenge with Influenza vaccine was positive. On an unknown date, the outcome of the guillain barre syndrome was recovered/resolved and the outcome of the guillain barre syndrome, hemiparesthesia, weakness, feeding disorder, respiratory failure, encephalomalacia and areflexia were recovering/resolving.   The reporter considered the guillain barre syndrome to be related to Influenza vaccine. The reporter considered the guillain barre syndrome, hemiparesthesia, weakness, feeding disorder, respiratory failure, encephalomalacia and areflexia to be related to Influenza vaccine.  Additional details were provided as follows: This case was reported in a literature article and described the occurrence of Recurrent Guillain-Barre Syndrome (GBS), in a male patient of unspecified age, who was vaccinated with Unspecified Influenza vaccine (manufacturer unknown) for prophylaxis.   No information on patient medical or family history or concurrent condition or concomitant medication was reported.  On an unknown date, the patient received Unspecified Influenza vaccine (administration site or route unspecified, dose not reported, batch number not provided). The age at vaccination was not reported.  On an unknown date in 2015, an unknown period after vaccination, the patient was diagnosed with GBS. The patient required 18 days of mechanical ventilation for GBS following influenza vaccination. At that time, the patient was treated with intravenous immunoglobulin (IVIG) and plasma exchange (PLEX) and made full recovery. The patient was eventually discharged to a long term acute care hospital.  On an unspecified date in 2020, the patient received Unspecified Influenza vaccine (administration site or route unspecified, dose not reported, batch number not provided). The age at vaccination was not reported but it could be between 63 years or 64 years at the time of vaccination. On an unknown date, unknown period after vaccination, the patient developed paresthesias of the right hemibody and weakness that progressed to inability to feed himself and ultimately respiratory failure 48 hours later. Approximately five weeks after receiving Influenza vaccine, the patient was admitted to an outside hospital. Magnetic resonance Imaging (MRI) of the neuraxis showed the prior right MCA stroke (Fluid-attenuated inversion recovery (FLAIR) sequence showed the encephalomalacia from the right middle cerebral artery (MCA) infarct). Initial evaluation in the neurosciences intensive care unit found him to be alert. The patient's negative inspiratory pressure (NIF) was -5cm H2O (normal more than 60 cm H2O) and right upper and lower extremity power 0/5 with 0/4 reflexes. The patient was on apixaban for atrial fibrillation; thus, initial lumbar puncture was deferred while waiting for clearance of the medication. Given patient history and examination, PLEX was started. The patient received 5 sessions over a period of 8 days. Lumbar puncture was performed and showed normal cell counts with elevated protein (108 mg/dl (normal 15-45 mg/dl)). Nerve conduction study (NCS) showed prolonged motor distal latencies and severely slowed conduction velocities with reduced compound motor action potential (CMAP). Sural sensory response was normal. F waves were absent. Electromyography (EMG) showed fibrillation potentials (+1) in the right deltoid along with severely decreased recruitment in the right triceps and right tibialis anterior. These diagnostic tests were consistent with GBS and the patient was diagnosed with recurrent GBS. At the age of 64 years, the patient with history remote right middle cerebral artery (MCA) stroke and left hemiplegia was transferred from an outside hospital for ascending weakness of the right hemibody, areflexia, and acute respiratory failure requiring intubation. The patient continued to improve clinically. By day seven, right upper extremity strength had improved to 3+/5 and lower extremity at least 3-/5 in proximal muscle groups. Patellar muscle stretch reflex improved to 1+/4 but Achilles reflex remained 0/4. The patient was successfully extubated and eventually transferred to a long term acute care hospital for anticipated long-term rehabilitation and treatment. The case was considered as serious due to hospitalization. The authors commented "We report a case of recurrent GBS. In both incidences, separated by approximately five years, the influenza vaccine was given within 6 weeks prior to symptom onset. There may be an increased risk for developing GBS from pandemic influenza vaccinations (such as H1N1) compared to seasonal vaccination. Notably, the patient described in our case did not meet all of the characteristics. He was older and had a classic GBS presentation. His presentation, however, was milder than his initial GBS. There likely is a genetic or immunologic host susceptibility that plays a role in recurrent GBS. The Advisory Committee on Immunization Practices currently notes a precaution for revaccination in patients with a history of GBS after an influenza vaccine. The committee also states that influenza vaccination may outweigh the possible risk for certain patients who have a history of GBS within six weeks of influenza vaccine if they are at higher risk for severe complications from influenza. Although recurrence risk is documented to be low, clear risk factors for recurrent GBS have not been consistently defined in the literature. Further studies are needed to determine which patients are at the highest risk for recurrent GBS".  The authors concluded "The risk of GBS following vaccination is low at one to three cases per million patients vaccinated. Additionally, the incidence of GBS recurrence after vaccines appears low but has not been well described. However, despite the low incidence, it is important to carefully weigh risks and benefits of revaccination."