Differential antibody response to COVID-19 vaccines across immunomodulatory therapies for multiple sclerosis

Background: Prior studies suggest reduced humoral response to COVID-19 vaccination in immunosuppressed populations. Disease modifying therapies (DMTs) for multiple sclerosis (MS) have variable immunomodulatory effects, and limited data are available for all DMTs. We aimed to determine the impact of DMTs on antibody response to COVID-19 vaccination among MS patients. Methods: Patients with documented COVID-19 vaccination dates and anti-spike antibody results post-vaccination were identified between March-August 2021. Clinical data were retrospectively abstracted from chart review. Deidentified data were analyzed to evaluate antibody response, and multivariable logistic regression analyses were used to identify clinical and demographic predictors of antibody response. Data analysis was completed with SAS Studio, v3.8. Results: A total of 353 individuals had documented COVID-19 vaccine and antibody test dates (58% Pfizer, 38% Moderna, and 4% Johnson & Johnson). Of these 353 patients, 72% developed antibodies, with a mean antibody test interval of 53 days (median 46) post final vaccine dose. 100% of those on no DMT (n = 34), injectables (n = 20), teriflunomide (n = 10), natalizumab (n = 71), and 97.8% of those on fumarates (n = 46/47) had a positive antibody result. One patient on cladribine (n = 1) had a negative antibody result. Of those on sphingosine-1 phosphate (S1P) modulators, 72.4% (n = 21/29) had a positive antibody result. Of those on anti-CD20 therapies, 37.6% (n = 53/141) had a positive antibody result. Multivariate modeling of the total cohort showed anti-CD20 therapy was significantly associated with lower odds of positive antibody response (OR = 0.024, 95% CI 0.01;0.05, p < 0.0001). Among S1P modulators, increased duration of therapy, and not lymphopenia, may be associated with lower odds of positive antibody response. Multivariate modeling of anti-CD20 therapies showed therapy duration < 1 year (OR 8.14, 95% CI 2.896;22.898 p <.0001) and prior COVID-19 infection (OR = 3.95, 95% CI 1.137;13.726, p =.03) were significantly associated with higher odds of a positive antibody response. In patients with recent B-cell data, mean B-cell count was higher in antibody-positive individuals compared to antibody-negative (32.9 vs. 3.9 cells, p =.0056). Conclusion: MS DMTs had variable impact on antibody response with mRNA and viral vector COVID-19 vaccines. All patients on no DMT, interferons, glatiramer acetate, teriflunomide, natalizumab, and nearly all on fumarates had positive antibody responses post-vaccine. S1P modulators and anti-CD20 therapies attenuated antibody response post-vaccine. For patients on anti-CD20 therapies, shorter duration of therapy and prior COVID-19 infection predicted positive antibody response. Further studies are needed to determine clinical significance of antibody testing, development of cellular mediated immunity, and benefits of booster vaccinations.