Suspected COVID-19 vaccine-associated Guillain-Barre syndrome; demyelinating neuropathies; This is a literature report for the following literature source(s):   An adult male patient received BNT162b2 (BNT162B2), as dose number unknown, single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. The following information was reported: GUILLAIN-BARRE SYNDROME (medically significant), outcome "unknown", described as "Suspected COVID-19 vaccine-associated Guillain-Barre syndrome"; DEMYELINATING POLYNEUROPATHY (medically significant), outcome "unknown", described as "demyelinating neuropathies". The patient underwent the following laboratory tests and procedures: CSF protein: unknown results. Clinical course: Four cases of acute and chronic demyelinating neuropathies following COVID-19 vaccination were seen at (Medical Center name withheld) from May to Sep2021. All were males, ages 26-83 years old. Two received the Pfizer-BioNTech vaccine, one Moderna, and one Johnson & Johnson. Onset ranged from 2-21 days after the final dose of vaccination. The time from symptom onset to neurological evaluation ranged from 3 weeks to 4 months, during which symptoms progressed. All cases presented with progressive numbness, weakness, and areflexia in all limbs; two had difficulty walking. Severe facial diplegia was seen in two cases and other bulbar symptoms in one other case. Three cases had electrophysiologic studies confirming demyelination while one case had findings of subacute polyradiculopathies. Cerebrospinal fluid protein was elevated in two cases and normal in the others. No cases had other co-morbidities or histories suggesting an alternate diagnosis. The diagnosis was acute inflammatory demyelinating polyneuropathy (AIDP) in one case, chronic demyelinating polyradiculoneuropathy (CIDP) in two, and subacute polyradiculopathies in one. The cases with AIDP and CIDP received treatment with intravenous immunoglobulin due to significant motor disability, while the case with subacute polyradiculopathies had spontaneous recovery within 8 weeks. Of the treated cases, two had significant improvement by outpatient follow-up at 2-4 weeks post-treatment and one had yet to follow up. Conclusions: Continued identification and reporting of demyelinating neuropathies following COVID-19 vaccination was essential to determine whether a causative association was present. Prompt evaluation for alternative etiologies are vital and early treatment was recommended.; Sender's Comments: Based on the information in the case report and a plausible temporal relationship, a possible causal association between the reported events and suspect drug BNT162B2 cannot be excluded. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate,Linked Report(s) : US-PFIZER INC-202200966005 Same article/drug/ event; different patient.;