ABSTRACT
Introduction: Most reports related to humoral immune response to COVID 19 vaccines in people with Multiple Sclerosis (pwMS) were performed on mRNA-based vaccines. Objective(s): to analyze the longitudinal humoral immune responses to adenovirus-based vaccines (Sputnik V and AZD1222) in pwMS under different diseases modifying therapies (DMTs) Methods: IgG anti- SARS-COV-2 spike titers in a cohort of 101 pwMS and 28 healthy controls (HC) were measured 6 weeks after vaccination using the COVID-AR kit according to the manufacture instructions. Both patients and controls received two or three doses of Sputnik, AZD1222 or a mixed schedule (MS) of both vaccines. The neutralizing capacity was evaluated by measuring antibody neutralizing titers using SARS COV-2 pseudotyped particles. Result(s): 60.5% of pwMS were female, mean EDSS: 2.49 +/-1.5, age: 36.6 +/-10.7, disease duration 7.6 +/- 5.1 years. DMTs: 45 pwMS were under fingolimod, 23 under dimethyl fumarate, 14 under cladribine and 19 under antiCD20 monoclonal antibodies. Vaccines: 35.7% Sputnik V, 51.9% AZD1222 and 12.4 % MS. No antibody response to a 2nd dose was found in 41.3% of pwMS under fingolimod and 73.6% under antiCD20. We found a correlation between lower lymphocyte count and lower antibody titers in pwMS under fingolimod (r: 0.67, 95% CI: 0.46-0.81, p=<=0.0001). A correlation was also found between the antibody titer and the last dose of antiCD20 (r: 0.49, 95% CI: 0.03-0.7, p=0.03). In March 2022, 57 pwMS received their 3nddose, 6 patients under fingolimod and 7 under antiCD20 remained without any antibody response. We did not find differences in the neutralization capacity with different DMT and or vaccines. Multivariate regression analysis showed antiCD20 (beta= -,349, 95% CI: -3655.6-369.01, p=0.017) and fingolimod (beta=-,399, 95% CI: -3363.8-250.9, p=0.023) treatments as independent factor associated with low antibody response (r2 adjusted=0.157). Conclusion(s): This is the first report of longitudinal humoral immune response of patients under adenovirus-based vaccines, specially Sputnik V, that demonstrate that these vaccines have similar results to those obtained with mRNA-based vaccines.