Guillain-Barre Syndrome/acute recurrent exacerbation of the AMSAN variant of GBS; gait instability/difficulty walking; endorsed feeling "wobbly/endorsed feeling particularly weak when standing needing to support himself with a wall to remain upright; unable to feel sensations in his fingers and toes; shortness of breath; respiratory distress; globally reduced pinprick sensation; reduced sensation to vibration; impaired proprioception bilaterally below the ankles.; absent deep tendon reflexes in the bilateral upper and lower extremities; weakness in his body/endorsed feeling particularly weak when standing needing to support himself with a wall to remain upright; recurrent, five-minute-long episodes of bilateral Shaking of hands which progressed to his entire body; leg weakness; leg weakness and gait instability lead to three falls; This case was reported in a literature article and described the occurrence of guillain barre syndrome in a adult male patient who received Herpes zoster (Shingrix) for prophylaxis.  The patient's past medical history included spinal operation (lumbar), total knee replacement (right), weakness generalized (developed weakness in his body), tremor (five-minute-long episodes of bilateral shaking of hands, which progressed to his entire body), lower extremities weakness of, unsteady gait, fall (leg weakness and gait instability lead to three falls), unsteadiness (need to support himself with a wall to remain upright when standing), emergency care (psychiatrist noticed his weakness and was encouraged to visit the emergency department), hypoesthesia, decreased vibratory sense (bilaterally below the ankles), loss of proprioception (impaired proprioception bilaterally below the ankles), tendon reflex absent (had absent deep tendon reflexes in the bilateral upper and lower extremities), guillain barre syndrome (AMSAN variant), hospitalization (upon arrival at the ED, the patient was admitted to neurology) and plasma exchange (five sessions of plasma exchange (PLEX)). Concurrent medical conditions included hypothyroidism, bipolar disorder, obstructive sleep apnea syndrome and hyperlipidemia. Additional patient notes included patient denied recent illnesses, gastrointestinal issues, or travel outside his home.   On an unknown date, the patient received the 2nd dose of Shingrix. On an unknown date, 2 weeks after receiving Shingrix, the patient experienced guillain barre syndrome (serious criteria hospitalization, GSK medically significant and clinically significant/intervention required), gait disturbance (serious criteria hospitalization), unsteadiness (serious criteria hospitalization), loss of sensation (serious criteria hospitalization), shortness of breath (serious criteria hospitalization), respiratory distress (serious criteria hospitalization and GSK medically significant), hypoesthesia (serious criteria hospitalization), decreased vibratory sense (serious criteria hospitalization), loss of proprioception (serious criteria hospitalization), tendon reflex absent (serious criteria hospitalization), weakness generalized (serious criteria hospitalization), tremor (serious criteria hospitalization), lower extremities weakness of (serious criteria hospitalization) and fall (serious criteria hospitalization). On an unknown date, the outcome of the guillain barre syndrome, gait disturbance, unsteadiness, loss of sensation, hypoesthesia, decreased vibratory sense, loss of proprioception, tendon reflex absent, weakness generalized, tremor, lower extremities weakness of and fall were recovering/resolving and the outcome of the shortness of breath and respiratory distress were unknown.   The reporter considered the guillain barre syndrome, gait disturbance, unsteadiness, loss of sensation, shortness of breath, respiratory distress, hypoesthesia, decreased vibratory sense, loss of proprioception, tendon reflex absent, weakness generalized, tremor, lower extremities weakness of and fall to be possibly related to Shingrix.     Additional Information: GSK Receipt Date: 29-NOV-2022 Reporter's comments: The patient was 61 years old at the time of initial episode. The patient was with a past medical history of hypothyroidism, bipolar disorder, obstructive sleep apnea, hyperlipidemia, lumbar spine surgery and right total knee replacement. Over the course of two weeks, the patient developed weakness in his body. He had recurrent, five-minute-long episodes of bilateral shaking of hands, which progressed to his entire body. His leg weakness and gait instability lead to three falls. The patient endorsed feeling particularly weak when standing and needing to support himself with a wall to remain upright. The patient denied experiencing vertigo, visual impairment, hearing loss, sensory impairment, headaches, or loss of consciousness. After visiting his psychiatrist, who noticed his weakness, he was encouraged to visit the emergency department (ED). Upon arrival at the ED, the patient was admitted to neurology and underwent further workup. The patient denied recent illnesses, gastrointestinal issues, or travel outside his home. Physical examination showed globally reduced pinprick sensation, reduced sensation to vibration bilaterally below the ankles, and impaired proprioception bilaterally below the ankles. The patient had absent deep tendon reflexes in the bilateral upper and lower extremities. Romberg sign was also present at the time of examination. The patient had no abnormalities on an initial complete blood count, comprehensive metabolic panel, and urinalysis. All hormones and inflammatory mediators were within normal limits. Extractable nuclear antigen panel (ENA), antinuclear antibody (ANA), anti-double stranded DNA (anti-DSDNA), anti-GQ-1B, and anti-GQ-1C were negative. A paraneoplastic panel revealed no abnormalities. Campylobacter jejuni antibodies were negative. A lumbar puncture revealed albuminocytological dissociation-elevated protein with normal leukocyte count. Nerve conduction and Electromyography (EMG) were also done and pointed to a diagnosis of the acute motor and sensory axonal neuropathy (AMSAN) variant of Guillain-Barre Syndrome (GBS). The patient had an elevated protein count. The leukocyte count, glucose and lactic acid were within normal limits. The patient received five sessions of plasma exchange (PLEX) every other day over the course of one week. He received four total sessions. He gradually experienced an improvement in motor and sensory parameters. He was discharged after eight days with referrals to outpatient physical/occupational therapy and neurology. Approximately 10 months later, the patient presented to his neurologist due to one week of difficulty walking. The patient endorsed feeling "wobbly" and unable to feel sensations in his fingers and toes. He also endorsed shortness of breath. Due to possible respiratory distress, his neurologist advised him to go to the emergency department. Upon arrival, the patient was again admitted. The patient denied recent illnesses, gastrointestinal issues, or travel outside his home. The patient said he received a second dose of Shingrix two weeks before symptoms started. Since his symptoms presented nearly identically to the first episode, the patient was diagnosed with acute recurrent exacerbation of the AMSAN variant of GBS. He was monitored for respiratory distress with pulmonary function testing every eight hours. Physical examination showed globally reduced pinprick sensation, reduced sensation to vibration bilaterally below the ankles, and impaired proprioception bilaterally below the ankles. The patient had absent deep tendon reflexes in the bilateral upper and lower extremities. Romberg's sign was unable to be assessed. The patient again received PLEX therapy daily for a total of four sessions. The patient experienced a complete improvement in motor strength. Sensation and reflexes continued to improve but had not yet returned to baseline. After five days of admission, the patient was discharged with recommendations to follow up with his neurologist. The patient had the AMSAN variant in both episodes. The patient had similar symptoms in each episode. His second episode presented with some respiratory distress in addition to previous symptoms similar to the previous episode. The patient was younger than the demographic the FDA released a black box warning for (adults aged 65 and older). This case highlights the difficulty of diagnosing and treating recurrent GBS. It also raises awareness that Shingrix may be related to the development of GBS in younger patients. This case also emphasizes the importance of differentiating GBS from other polyneuropathies. "In addition to the primary trial that showed a modestly increased risk of developing GBS following Shingrix administration, there have been several case reports of this phenomenon. Additionally, recurrent GBS is still poorly understood and its relationship to Shingrix is actively being researched. To our knowledge, this is the first case of GBS recurrence following vaccination with Shingrix. In general, providers are recommended to educate the patient on the efficacy and benefit of vaccines and monitor for any potential GBS-like symptoms following vaccination. Clinicians should be specifically cautious for patients of any age, with a past history of GBS, who are receiving the Shingrix vaccine". Additional supportive information: The article corresponding to this case is not available for regulatory submission due to copyright restriction.