Serological response to SARS-CoV-2 vaccination in multiple sclerosis patients treated with fingolimod or ocrelizumab: an initial real-life experience.

Recent observations suggest a lack of humoral response after SARS-CoV-2 vaccination in multiple sclerosis (MS) patients treated with fingolimod or ocrelizumab To assess serological response to SARS-CoV-2 vaccination in MS patients receiving these disease-modifying treatments (DMTs) in a real-life setting. Retrospective clinical data collection from MS patients followed at San Raffaele Hospital MS Centre (Milan, Italy). All patients treated with fingolimod or ocrelizumab who had received a complete anti-COVID-19 vaccination course, with no clinical history suggestive of previous SARS-CoV-2 infection and with an available post-vaccination serological assay obtained at least 14 days after vaccination completion were considered for the study. We collected data from 32 MS patients, 16 treated with fingolimod and 16 receiving ocrelizumab. Among the fingolimod group 10 patients (62.5%) had a positive serological response after vaccination and among ocrelizumab-treated patients a positive serological test was found in six cases (37.5%). No relation between serological response and clinical features (i.e., treatment duration, time between vaccination and last treatment dose, and white blood cells count) was identified. Our initial real-life experience suggests a variable antibody production in MS patients receiving these DMTs. At present, there are no sufficient data to do not recommend anti-SARS-CoV-2 vaccine in these patients.