Epidemiologic studies on coronavirus disease 2019 (COVID-19) in patients with multiple sclerosis (pwMS) have focused on the first waves of the pandemic until early 2021.
We aimed to extend these data from the onset of the pandemic to the global coverage by vaccination in summer 2022.
This retrospective, multicenter observational study analyzed COVISEP registry data on reported COVID-19 cases in pwMS between January 2020 and July 2022. Severe COVID-19 was defined as hospitalization or higher severity.
Among 2584 pwMS with confirmed/highly suspected COVID-19, severe infection rates declined from 14.6% preomicron wave to 5.7% during omicron wave (p < 0.001). Multivariate analysis identified age (odds ratio (OR) = 1.43, 95% confidence interval (CI) = [1.25-1.64] per 10 years), male sex (OR = 2.01, 95% CI = [1.51-2.67]), obesity (OR = 2.36, 95% CI = [1.52-3.68]), cardiac comorbidities (OR = 2.36, 95% CI = [1.46-3.83]), higher Expanded Disability Status Scale (EDSS) scores (OR = 2.09, 95% CI = [1.43-3.06] for EDSS 3-5.5 and OR = 4.53, 95% CI = [3.04-6.75] for EDSS ⩾6), and anti-CD20 therapies (OR = 2.67, 95% CI = [1.85-3.87]) as risk factors for COVID-19 severity. Vaccinated individuals experienced less severe COVID-19, whether on (risk ratio (RR) = 0.64, 95% CI = [0.60-0.69]) or off (RR = 0.32, 95% CI = [0.30-0.33]) anti-CD20.
In pwMS, consistent risk factors were anti-CD20 therapies and neurological disability, emerging as vital drivers of COVID-19 severity regardless of wave, period, or vaccination status.