Anti-CD20 disease modifying therapies decrease the humoral response to COVID-19 mRNA vaccination in patients with multiple sclerosis

Introduction: COVID-19 pandemic allowed scientific world to develop an effective vaccine against the virus in record time. The clinical trials done for inactivated vaccine (coronavac) and mRNA (Pfizer) did not include people with multiple sclerosis (pwMS). Objective: To determine if pwMS can have humoral response to COVID-19 vaccine. Aim: to determine COVID-19 humoral response after vaccination with coronavac or Pfizer in pwMS currently being treated or naive to treatment. Methods: 103 patients of the Clinica Alemana cohort who agreed to the detection of the humoral response (IgG) after vaccination with coronavac o Pfizer vaccine against COVID-19. We obtained demographic data and IgG levels (baseline and 4 weeks after the second dose of the vaccine) for each patient. Results: 103 patients agreed to participate, 2 have not yet received the vaccine (waiting list according to the national plan of vaccination). Demographics: 69% female, mean age 36.93+10.78, EDSS 1.81+1.66, 91% were relapsing remitting, 6% were secondary progressive, 3% were primary progressive, 11% naive to treatment, 76.70% received both vaccine doses (68% coronavac and 32% Pfizer). Patients currently being treated with interferons, glatiramer acetate, teriflunomide, dimethyfumarate and natalizumab were able to have humoral response to coronavac;18/19 patients with cladribine responded to the vaccine, either coronavac or Pfizer. The patient that did not respond was previously treated with anti CD-20 therapy. All 4 patients treated with alemtuzumab also responded to coronavac. Interestingly 2/3 patients treated with fingolimod had humoral response to coronavac. Regarding anti CD20 therapy, only 16.67% of the patients had humoral response (3 to coronavac and 1 patient to Pfizer). The time between antiCD20 infusion and the vaccine ranged from 2 -18 months, for alemtuzumab ranged from 2-12 months and for cladribine was 2 weeks - 12 months. Conclusions: In our cohort, most of the treatments are likely to produce humoral response to the COVID-19 vaccine, especially alemtuzumab, cladribine and natalizumab, regardless the infusion/ administration time. Further study needs to be done that includes more patients with antiCD20 and fingolimod but also it is important that the studies take into consideration the type of vaccine (T cell dependent response), B cell reconstitution and lymphocyte subpopulations for B and T cells.