The Impact of Disease-Modifying Therapies of Multiple Sclerosis on the Effectiveness of the BBIBP-CorV COVID-19 Vaccine

Background: It is well-known that disease-modifying therapies (DMTs) in patients with multiple sclerosis (PwMS) may reduce the immune response to COVID-19 vaccines. Objectives: The present study aimed to investigate the efficacy of the Sinopharm/BBIBP-CorV vaccine in Iranian PwMS treated with different DMTs. Methods: This quasi-experimental study was conducted between January 2021 and January 2022 at the MS clinics of Imam Hossein and Qaem Hospitals in Tehran and Mashhad, Iran. Based on inclusion and exclusion criteria, PwMS received two doses of the Sinopharm vaccine at an interval of 28 days. The humoral response to the vaccine was evaluated by measuring the IgG receptor-binding domain (RBD-IgG) against SARS-CoV-2 on three occasions: before vaccination, 28 days after the first dose, and 28 days after the second dose. Results: Of the 208 patients, 117 were eligible for analysis. The Sinopharm vaccine was generally safe among Iranian PwMS. The IgG antibody titer against the SARS-CoV-2 strain was significantly associated with the DMT class. Patients treated with fingolimod and rituximab developed the lowest humoral response to the Sinopharm vaccine (21.1% and 38.4%, respectively). Conclusions: The present study revealed that PwMS treated with fingolimod and rituximab are likely to have a suboptimal humoral response to the Sinopharm vaccine. This finding may help neurologists make informed decisions about DMT selection during the pandemic.