Guillain-Barre syndrome following COVID-19 vaccines: A scoping review.

Guillain-Barre syndrome following COVID-19 vaccines (GBSfCV19v) is a reported adverse effect that remains unclear. We present a structured review based on two case reports of GBSfCV19v, a systematic review, and Vaccine Adverse Event Reporting System (VAERS) analysis to estimate the risk and describe the clinical characteristics (CC) of these events. We've searched on MEDLINE and Embase, from the inception to May 20, 2021, using the keywords: "Guillain barre syndrome" and cross-referenced with "covid-19 vaccines." We estimated the risk of GBSfCV19v, comparing it with the risk of GBS following the influenza vaccine (GBSfIv), considering the VAERS sensitivity. The clinical characteristics included: age, sex, comorbidities, type of vaccine, administered dose, clinical onset, deaths, cerebrospinal fluid (CSF), and electromyography (EMG) pattern. We found 43 cases, considering the risk of GBSfCV19v lower than GBSfIv (160-320 cases). The patients had a mean age of 54 years and 23 (56%) were male. The types of vaccines used: Pfizer (22), Moderna (9), AstraZeneca (3), Janssen (3), and Johnson & Johnson (1). 24 cases of GBS occurred after the first dose, with clinical onset of 7 days. CSF albuminocytological dissociation was reported in 7 patients, and EMG revealed a predominant demyelinating pattern. GBSfCV19v risk appears to be lower than what was expected from other respiratory virus vaccines. Most cases of GBS were middle-aged males within a week following the first dose of the COVID-19 vaccine, showing a typical demyelinating neuropathy with albuminocytological dissociation.