The study of COVID-19 infection following vaccination in patients with multiple sclerosis

Abstract Background At this time vaccination against SARS-CoV2 is a global priority. Cases with multiple sclerosis (MS) were among the first vaccinated populations in Iran. We evaluated the change in the frequency of COVID-19 after vaccination and the associated factors with severe COVID-19 infection before and after full vaccination. Methods A questionnaire was validated to investigate the basic characteristics (age, gender, education, body mass index, smoking status, and comorbidities), MS disease and treatment status (MS type, MS duration, The Expanded Disability Status Scale (EDSS), disease modifying treatments) and the information about COVID-19 infection and severity. Results 692 (91.9%) of participants have received both doses of vaccines, of which Sinopharm appeared to be the most common type. Significant difference of COVID-19 infection prevalence was seen before vaccination and after full vaccination (difference: 0.16, 95% CI: 0.12–0.20) (p value  Discussion The decreased frequency of infection with SARS-CoV2 was predictable but the insignificant difference in cases with the severe forms of the disease raise concern. The only significant predictor was found to be severe allergic reactions. As there are debates on antiCD20 s association with severe COVID-19 and vaccine efficacy, we could not find such significant relation. The other noticeable point about the found relation of EDSS and critical COVID-19 before vaccination is the absence of such relation after full vaccination.