multiple sclerosis(15) COVID-19(12) Patient(12) analysed(11) humoral immune response(11) Infection(9) SARS-CoV-2(9) titre(8) patients(7) IgG(7) T cell response(7) Infectious diseases(7) B cell(7) therapy(7) risk(7) vaccination(7) receiving(7) Immune cell(7) disorder(6) Virology(6) stroke(5) clinical neurology(5) collected(5) cohort of patient(5) 95% CI(4) positively correlated(4) Cell-mediated immunity(4) profile(4) time(4) parameter(4)