ABSTRACT
Objective: To examine the temporal trends of humoral and cell-mediated immune responses to SARS-CoV-2 mRNA vaccines among multiple sclerosis (MS) patients on different immunomodulatory therapies. Background: The impact of various MS medications on the immune responses to SARS-CoV-2 vaccine is of acute interest to patients and clinicians. Design/Methods: 22 MS patients treated with ocrelizumab (OCR, n=9), natalizumab (NTZ, n=8), fumarates (FUM, n=5;diroximel fumarate, 3 and dimethyl fumarate, 2) received BNT162b2 (Pfizer, n=15) or mRNA-1273 (Moderna, n=7) vaccines. Blood samples were collected before and after each of the two vaccine doses, and 2 months after second vaccine dose. AntiSARS-CoV-2 spike protein titers were measured using quantitative assay (Labcorp). Antibody neutralization was measured with a lentivirus-based pseudovirus particle expressing the D614 spike protein (Labcorp-Monogram Biosciences). T-cell reactivity was determined by measuring interferon-gamma and interleukin-2 in response to stimulation with SARS-CoV-2 peptides. Results: All patients in NTZ and FUM cohorts, but only 22% (2/9) of OCR cohort developed anti-spike and neutralizing antibodies. The highest titers were measured after the second vaccine dose, without significant difference between the NTZ and FUM cohorts in anti-spike IgG (69.7+/-55.1 vs 56.0+/-36.7 arbitrary units/ml) or neutralizing ID50 (1513+/-1317 vs 942+/ -566). Two months after the second vaccine, the antibody titers and neutralizing ID50 decreased by 72% and 79% in NTZ cohort, respectively, and by 45% and 49% in FUM cohort. T-cell reactivity was observed in all cohorts as early as 7 days after the first vaccine, and further increased following the second vaccine. Conclusions: Patients on NTZ and FUM mounted robust antibody responses to SARS-CoV-2 mRNA vaccines, in contrast to OCR-treated patients. T-cell responses were comparable among all three treatment cohorts. Two months after the second vaccine, the serological responses decreased by 45-79%. These findings may inform the optimal timing of additional vaccine doses for MS patients.