Safety profile of SARS-CoV-2 vaccination in patients with antibody-mediated CNS disorders

Objectives: In this retrospective multicenter study, we evaluated the safety of SARS-CoV-2 vaccination in patients harboring autoantibodies targeting neuronal surface and/or synaptic antigens. Methods: From eight Italian Neurology Units, we included patients with: a) serum and/or CSF positivity for specific neuronal autoantibodies; b) a compatible neurological syndrome; and c) available follow-up ≥6 weeks after vaccination with any of the approved SARS-CoV-2 vaccines. Demographics, clinical data, and information regarding previous SARS-CoV-2 infection and vaccination were collected. Disease relapses were considered "post-infectious" or "post-vaccination" when occurring within 6 weeks from infection/vaccination. Results: We included 66 patients; 7/66 (11%) had a previous history of SARS-CoV-2 infection and 1/7 (14%) had post-infection relapses. BNT162b2-Pfizer-BioNTec was administered in 55 cases (83.3%) and mRNA-1273-Moderna in 11 (16.7%). The median number of doses administered per patient was 2 (1-3) and >50% of patients did not experience side effects. Five patients (8%) had post-vaccination relapses (seizure 3/5); 4/5 improved after immunotherapy, while one did not receive immunotherapy and worsened. Patients with post-vaccination relapses had higher disability scores at vaccination (p = 0.025), a trend favoring Leucine-rich glioma-inactivated protein 1 LGI1 glutamic acid decarboxylase 65 (GAD65) antibodies (p =  0.054) and shorter time from last relapse (p = 0.057). Discussion: Our data support the safety of SARS-CoV-2 vaccines in patients with neurological disorders associated with antibodies to neuronal and synaptic antigens.