Guillain-Barre Syndrome - suspected; unable to bend toes/mobility is impaired and he has to walk with a cane; abnormal spinal tap - increased protein; vertigo; first Shingrix dose on 26-OCT-2022 and the second dose on 7-DEC-2022; This serious case was reported by a consumer via call center representative and described the occurrence of vertigo in a 77-year-old male patient who received Herpes zoster (Shingrix) for prophylaxis.   Concurrent medical conditions included rheumatoid arthritis and atrial fibrillation. Concomitant products included VARICELLA ZOSTER VACCINE RGE (CHO) (SHINGRIX), adalimumab (Humira) and medication unknown (Blood Thinner).   On 07-DEC-2022, the patient received the 2nd dose of Shingrix (intramuscular, unknown deltoid). On 07-DEC-2022, an unknown time after receiving Shingrix, the patient experienced drug dose administration interval too short (Verbatim: first Shingrix dose on 26-OCT-2022 and the second dose on 7-DEC-2022). In AUG-2023, the patient experienced vertigo (Verbatim: vertigo) (serious criteria hospitalization). On an unknown date, the patient experienced guillain barre syndrome (Verbatim: Guillain-Barre Syndrome - suspected) (serious criteria hospitalization and GSK medically significant), mobility decreased (Verbatim: unable to bend toes/mobility is impaired and he has to walk with a cane) (serious criteria hospitalization) and cerebrospinal fluid protein abnormal (Verbatim: abnormal spinal tap - increased protein) (serious criteria hospitalization and GSK medically significant).  The outcome of the vertigo, guillain barre syndrome, mobility decreased and cerebrospinal fluid protein abnormal were not resolved and the outcome of the drug dose administration interval too short was unknown.   It was unknown if the reporter considered the vertigo, guillain barre syndrome, mobility decreased, cerebrospinal fluid protein abnormal and drug dose administration interval too short to be related to Shingrix.     It was unknown if the company considered the vertigo, guillain barre syndrome, mobility decreased, cerebrospinal fluid protein abnormal and drug dose administration interval too short to be related to Shingrix.   Additional Information: GSK receipt date: 18-Sept-2023 The reporter was the patient's wife.  The patient received the second dose and about eight months after the second Shingrix dose, in early August 2023, the patient developed vertigo. He saw his primary care physician and received a medication for vertigo but the medication did not lessen the vertigo and no cause was determined.  Soon after the onset of vertigo, he suddenly could not bend his toes, his mobility was impaired and he had to walk with a cane.   His neurologist admitted him to the hospital for testing. Due to the symptoms and spinal tap results, the neurologist was 75 percent sure that he patient had Guillain-Barre Syndrome.  At the onset of these event, the patient was also on Humira for rheumatoid arthritis. Humira was recently withdrawn due to these events.  The patient will see a hemotologist to rule out cancer.  He also has an appointment with a neuromuscular doctor in January 2024 to confirm the Guillain-Barre Syndrome diagnosis.  Nothing else was reported. The reporter consented to follow up. The patient received second dose of Shingrix earlier than the recommended interval, which led to shortening of vaccine schedule.