ABSTRACT
BACKGROUND: The impact of disease-modifying treatments on humoral response induced by inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is understudied. METHODS: We recruited 34 persons with multiple sclerosis (MS) under fingolimod treatment and 25 healthy individuals. Anti-SARS-CoV-2 spike IgG indices were measured by ELISA in sera of participants after CoronaVac vaccinations. RESULTS: Persons with MS displayed significantly lower antibody levels and seropositivity prevalence. Persons with MS with longer fingolimod treatment durations displayed lower anti-SARS-CoV-2 indices. CONCLUSION: Our results support previous findings regarding humoral response impairing effect of fingolimod after vaccinations. Patients under fingolimod treatment may require closer monitoring for COVID-19.