Background: Vaccination against the coronavirus disease 2019 (COVID-19) is recommended for patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). However, vaccine safety in these patients taking immunotherapeutic agents is unclear as they were not included in the vaccine trials.

Objective: To evaluate the safety of COVID-19 vaccines in patients with MS, NMOSD, and MOGAD.

Methods: We reviewed the medical records of MS, NMOSD, and MOGAD patients at the Keimyung University Dongsan Hospital. Information regarding vaccination schedules and adverse events was collected.

Results: A total of 56 patients (19, 22, and 15 patients with MS, NMOSD, and MOGAD, respectively) with a median age of 48.18 ± 15.72 years (range, 16-81 years) were included. Of them, 42 (75.0%) were female. In total, 76.8% (43/56) of all patients were vaccinated, and the vaccination rate was the highest for NMOSD patients (81.8%) and the lowest for MS patients (68.4%). All vaccinated patients were administered mRNA vaccines at least once in single or multiple vaccination doses. Only 3 of 43 (7.0%) vaccinated patients experienced clinical relapse following vaccination. Facial sensory changes with a brainstem lesion developed in an MS patient taking dimethyl fumarate, while myelitis occurred in a MOGAD patient receiving azathioprine maintenance therapy. The first episode of optic neuritis occurred in a patient who was later diagnosed with MOGAD.

Conclusions: Our study demonstrated a favorable safety profile with no serious adverse events associated with COVID-19 vaccines in patients with MS, NMOSD, and MOGAD.