Effect of multiple sclerosis disease-modifying therapies on the real-world effectiveness of two doses of BBIBP-CorV (Sinopharm) vaccine

Background: Immunogenicity data shows blunted responses to COVID-19 vaccination among people with MS (pwMS) on certain disease-modifying therapies (DMTs). Still, it is uncertain how this data translates into the clinic.Objective: To assess the effect of DMTs and other factors on the effectiveness of inactivated vaccination in pwMS.Methods: This cohort study was conducted in a period in which Iran experienced two COVID-19 peaks caused by the Delta variant. We used multivariable cox regression to compare COVID-19-free survivals, and an ordinal logistic model to compare COVID-19 severity between vaccinated pwMS on different DMTs.Results: A total of 617 pwMS were included in the final analysis, with a mean [SD] follow-up of 25.59 weeks [5.48] after their second dose. Laboratory/imaging-confirmed breakthrough COVID-19 occurred in 15/277 (5.41%) of injectable-treated (reference), 10/61 (16.39%) of fingolimod-treated (adjusted hazard ratio (aHR) [95% confidence interval (CI)]: 2.80 [1.24, 6.29]; P = 0.01), 9/128 (7.03%) of other oral-treated (aHR [95%CI]: 1.16 [0.50, 2.68]; P = 0.73), 19/145 (13.10%) of anti-CD20-treated (aHR [95%CI]: 2.11 [1.05, 4.22]; P = 0.04), and 6/56 (10.71%) of non-treated pwMS (aHR [95%CI]: 1.52 [0.57, 4.04]; P = 0.40). Age (adjusted Odds Ratio [aOR] [95%CI]: 1.05 [1.00, 1.10], P = 0.05) number of comorbidities (aOR [95%CI]: 2.05 [1.06, 3.96], P = 0.03), fingolimod therapy (aOR [95%CI]: 10.39 [2.47, 43.62], P < 0.01), and anti-CD20 therapy (aOR [95%CI]: 4.44 [1.49, 13.23], P < 0.01) were independently associated with a more severe COVID-19 course. Conclusion: The observed results stress the importance of developing personalized vaccination schedules and reservation of COVID-19 treatment resources for older pwMS with comorbidities receiving fingolimod or anti-CD20 therapies.