ABSTRACT
BACKGROUND: Since vaccination against coronavirus disease 2019 (COVID-19) became available, risks related to vaccinating patients with multiple sclerosis (MS) need to be carefully assessed. OBJECTIVE: Characterize safety and occurrence of immediate relapses following COVID-19 vaccination in a large cohort of MS patients. METHODS: We assessed the safety of BNT162b2 COVID-19 vaccination in adult MS patients. RESULTS: Between 20 December 2020 and 25 January 2021, 555 MS patients received the first dose of BNT162b2 vaccine and 435 received the second dose. There were three cases of COVID-19 infection encountered after the first dose. Safety profile of COVID-19 vaccine was characterized by pain at the injection site, fatigue, and headache. No increased risk of relapse activity was noted over a median follow-up of 20 and 38 days after first and second vaccine doses, respectively. The rate of patients with acute relapse was 2.1% and 1.6% following the first and second doses, respectively, similar to the rate in non-vaccinating patients during the corresponding period. Mild increase in the rate of adverse events was noted in younger patients (18-55 years), among patients with lower disability (Expanded Disability Status Scale (EDSS) ⩽3.0), and in patients treated with immunomodulatory drugs. CONCLUSION: COVID-19 BNT162b2 vaccine proved safe for MS patients. No increased risk of relapse activity was noted.