Immunity following SARS-CoV-2 vaccination in autoimmune neurological disorders treated with rituximab or ocrelizumab

ABSTRACT

Introduction: B cell-depleting therapy targeting CD20 molecule with rituximab (RTX) or ocrelizumab (OCR) affects humoral immune response after vaccination. It remains unclear whether these therapies influence T-cell-mediated immune response against SARS-CoV-2 after immunization. Aim(s) We aimed to evaluate the humoral and cellular immune response to the COVID-19 vaccine in a cohort of patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myasthenia gravis (MG). Method(s) Patients with MS (83), NMOSD (19), MG (7) under RTX (n=47) or OCR treatment (n=62) were vaccinated twice with mRNA BNT162b2 vaccine. Antibodies were quantified using the SARS-CoV-2- IgG chemiluminescence immunoassay targeting the spike protein. SARS-CoV-2-specific T-cell responses were quantified by interferon gamma release assays (IGRA). Immunocompetent vaccinated individuals (n=41) were included as controls. Result(s) Almost all immunocompetent controls developed antibodies against the SARS-CoV-2 trimeric spike protein, but only 42.05% of the patients under anti-CD20 (RTX or OCR) treatment seroconverted. There was no correlation between circulating B cells and the levels of antibodies. Even patients with a low proportion of circulating CD19+ B cells (<1%, 71 patients) had detectable SARS-CoV-2 specific antibody responses. This response was even higher in patients with longer than 3 weeks intervals of vaccination. SARS-CoV-2 specific T cell response measured by released interferon gamma was detected in 94.39% of the patients, independently of a humoral immune response. Conclusion(s) The majority of MS and NMOSD patients developed SARS-CoV-2-specific T cell response. The data suggest that vaccination can induce SARS-CoV-2-specific antibodies in a part of anti-CD20 treated patients. The response represented by levels of antibodies was better in individuals, who completed vaccination within more than 3 weeks.