Reports of Guillain-Barre Syndrome Following COVID-19 Vaccination in the USA: An Analysis of the VAERS Database

Background and Purpose An association between Guillain-Barre syndrome and its vari-ants (GBS/V) and vaccines has led to hesitancy toward vaccination. COVID-19 vaccines could theoretically provoke GBS/V via immune activation. We analyzed reports of GBS/V af-ter COVID-19 vaccination in the vaccine adverse event reporting system (VAERS).Methods The VAERS database is a surveillance system used to report vaccination events in the USA, and is open for consumers and physicians to access. It was queried for reports of GBS/V following COVID-19 vaccination. Reports were reviewed by four neurologists. Modi-fied diagnostic criteria were used to classify reports into definite, possible, and not GBS/V or insufficient data. Descriptive statistics were used to describe the sample, chi-square tests and one-way ANOVAs were used to compare intergroup differences, and t-test were used to com-pare group means.Results In 2021, 815 reports of GBS/V were filed. The completion rate for the variables in VAERS was 93.5%. The median age was 55 years (interquartile range [IQR]=5-86 years) and 50% of the subjects were male. The median time of onset was 10 days (IQR=0-298 days), 11% reported onset on the day of vaccination, and 13% reported onset after 6 weeks. Hospitaliza-tion was reported by 77%, with a median stay of 7 days (IQR=1-150 days). Lack of recovery, permanent disability, and death constituted 57%, 46%, and 2% of the reports, respectively. Based on GBS/V criteria, 47% of the cases were definite, 16% were possible, and 37% were not GBS/V or insufficient data. An alternate diagnosis was provided in 9% of cases.Conclusions GBS/V reports following COVID-19 vaccination were common, but many oc-curred outside of the expected timelines for GBS/V. Only 47% of cases represented definite GBS/V.