Abstract
Since 2019, a new coronavirus infection (COVID-19) due to an agent called SARS-CoV-2 spread rapidly worldwide. Patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMO-SD) are often treated with immunosuppressants. Beyond their effect on the risk of COVID-19 infection, the consequences on the long-term immune response against the coronavirus remain unknown. Among 13 MS or NMOSD patients with confirmed COVID-19 included, all 5 patients treated with anti-CD20 therapies had a negative SARS-CoV-2 serology. To date, maximal precautions to prevent coronavirus infection should be maintained in MS/NMOSD patients already exposed to COVID-19 during anti-CD20 therapy.