Objective To investigate features of Guillain-Barré syndrome (GBS) following SARS-CoV-2 vaccines and evaluate for a causal link between the two. Methods We captured cases of GBS after SARS-CoV-2 vaccination through a national, open-access, online surveillance system. For each case, the certainty of GBS was graded using the Brighton criteria, and the relationship to the vaccine was examined using modified WHO Causality Assessment criteria. We compared age distribution of cases with that of prepandemic GBS cases and clinical features with the International GBS Outcome Study (IGOS). Results Between 1 January and 30 June 2021, we received 67 reports of GBS following the ChAdOx1 vaccine (65 first doses) and three reports following the BNT162b2 vaccine (all first doses). The causal association with the vaccine was classified as probable for 56 (80%, all ChAdOx1), possible for 12 (17%, 10 ChAdOx1) and unlikely for two (3%, 1 ChAdOx1). A greater proportion of cases occurred in the 50-59 age group in comparison with prepandemic GBS. Most common clinical variants were sensorimotor GBS (n=55; 79%) and facial diplegia with paraesthesias (n=10; 14%). 10% (n=7/69) of patients reported an antecedent infection, compared with 77% (n=502/652) of the IGOS cohort (p<0.00001). Facial weakness (63% (n=44/70) vs 36% (n=220/620); p<0.00001) and sensory dysfunction (93% (n=63/68) vs 69% (n=408/588); p=0.00005) were more common but disease severity and outcomes were similar to the IGOS study. Interpretation Most reports of GBS followed the first dose of ChAdOx1 vaccine. While our study cannot confirm or refute causation, this observation, together with the absence of alternative aetiologies, different than expected age distribution and the presence of unusual clinical features support a causal link. Clinicians and surveillance bodies should remain vigilant to the possibility of this very rare adverse event and its atypical variants.
Bibliographical noteFunding Information:
We would like to thank the Association of British Neurologists for hosting the online reporting system, the Medicines and Healthcare products Regulatory Agency for support, and Professor Hugh Willison for helpful discussions. This work was supported by funding from the National Institute for Health Research (NIHR) and the UK Medical Research Council.
AAT is funded by the UK NIHR via academic clinical fellowship scheme (Award No. ACF-2020-07-003). TS is supported by the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections (Grant No. NIHR200907), NIHR Global Health Research Group on Brain Infections (No. 17/63/110) and the UK Medical Research Council’s Global Effort on COVID-19 Programme (MR/V03). TS is the president of the Encephalitis Society. BCJ received unrestricted research grants for work outside the current study from Baxalta, Grifols, CSL-Behring, Annexon, Hansa Biooharma, Prinses Beatrix Spierfonds, Horizon 2020 and GBS-CIDP Foundation International. BCJ also received consultancy fees from Roche for activities outside of the current study and is a chair of Steering Committee of International GBS Outcome Study (IGOS). BS reports non-financial support from UK NIHR Global Health Research Group on Brain Infections, grants from DHSC-UKRI Global Effort on COVID-19 (GECO) Research Grant for COVID-Neurological Disease global health research programme, outside the submitted work; and is a Clinical Management Consultant for WHO South-East Asia Regional Office, via GOARN, since April 2020 with focus on COVID-19 but not involved in any postvaccination work as part of the role. BDM received honoraria for lectures to SCRIPPS and Valneva. KB received support from CSL Behring to travel to the peripheral nerve society meeting in 2019. HM is funded by the NIHR Health Protection Research Unit in Vaccines and Immunisation.
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