Difference in safety and humoral response to mRNA SARS-CoV-2 vaccines in patients with autoimmune neurological disorders: the ANCOVAX study

Background Assessing the safety of SARS-CoV-2 mRNA vaccines and the effect of immunotherapies on the seroconversion rate in patients with autoimmune neurological conditions (ANC) is relevant to clinical practice. Our aim was to assess the antibody response to and safety of SARS-CoV-2 mRNA vaccines in ANC. Methods This longitudinal study included ANC patients vaccinated with two doses of BNT162b2 or mRNA-1273 between March and August 2021. Side effects were assessed 2–10 days after each dose. Neurological status and anti-spike receptor binding domain antibody levels were evaluated before vaccination and 4 weeks after the second dose. Healthcare-workers served as controls for antibody levels. Results We included 300 ANC patients (median age 52, IQR 40–65), and 347 healthcare-workers (median age 45, IQR 34–54). mRNA-1273 vaccine was associated with an increased risk of both local (OR 2.52 95% CI 1.45–4.39, p = 0.001) and systemic reactions (OR 2.51% CI 1.49–4.23, p = 0.001). The incidence of relapse was not different before and after vaccine (Incidence rate ratio 0.72, 95% CI 0.29–1.83). Anti-SARS-CoV-2 IgG were detected in 268 (89.9%) patients and in all controls ( p