Guillain-Barre syndrome; Condition exacerbated; This literature-non-study case was reported in a literature article and describes the occurrence of GUILLAIN-BARRE SYNDROME (Guillain-Barre syndrome) in an 80-year-old male patient who received mRNA-1273 (Spikevax) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    No Medical History information was reported.   On an unknown date, the patient received second dose of mRNA-1273 (Spikevax) (unknown route) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Spikevax) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient experienced GUILLAIN-BARRE SYNDROME (Guillain-Barre syndrome) (seriousness criterion medically significant) and CONDITION AGGRAVATED (Condition exacerbated). At the time of the report, GUILLAIN-BARRE SYNDROME (Guillain-Barre syndrome) was resolving and CONDITION AGGRAVATED (Condition exacerbated) outcome was unknown. Related    DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Electromyogram: consistent with the diagnosis of gbs Consistent with the diagnosis of GBS. On an unknown date, Lumbar puncture: consistent with the diagnosis of gbs Consistent with the diagnosis of GBS. On an unknown date, Nerve conduction studies: consistent with the diagnosis of gbs Consistent with the diagnosis of GBS. On an unknown date, Physical examination: consistent with the diagnosis of gbs Consistent with the diagnosis of GBS.     For mRNA-1273 (Spikevax) (Unknown), the reporter considered GUILLAIN-BARRE SYNDROME (Guillain-Barre syndrome) and CONDITION AGGRAVATED (Condition exacerbated) to be related.    Concomitant medication was not reported. The patient received treatment with intravenous immunoglobulin and there was significant improvement toward the end of 5th day.  It was reported that the patient was presented with chief complaints of progressive, ascending bilateral lower extremity paresthesia and weakness following first dose of Moderna vaccine. Symptoms got exacerbated after 2nd dose.  Company comment: This is a literature-non-study case (abstract review) concerning an 80-year-old male patient, with no medical history reported, who experienced the serious (medically significant) unexpected AESI of Guillain-Barre Syndrome after the first dose of mRNA-1273. Clinical examination and investigation findings including lumbar puncture, nerve conduction study, and electromyography were consistent with the diagnosis of GBS (specific results were not provided in the source document). His symptoms got exacerbated after 2nd dose. The patient received treatment with intravenous immunoglobulin and there was significant improvement toward the end of 5th day. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.; Sender's Comments: This is a literature-non-study case (abstract review) concerning an 80-year-old male patient, with no medical history reported, who experienced the serious (medically significant) unexpected AESI of Guillain-Barre Syndrome after the first dose of mRNA-1273. Clinical examination and investigation findings including lumbar puncture, nerve conduction study, and electromyography were consistent with the diagnosis of GBS (specific results were not provided in the source document). His symptoms got exacerbated after 2nd dose. The patient received treatment with intravenous immunoglobulin and there was significant improvement toward the end of 5th day. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.