Did COVID-19 Pandemic Change the Course of Multiple Sclerosis? A Retrospective Eight-Year Study

The COVID-19 pandemic was a special situation for patients treated with disease-modifying therapies (DMTs). Infections may provoke disease activity and determine the choice of DMTs. Moreover, DMTs create a potentially increased risk of infections. The study aimed to assess the impact of the COVID-19 pandemic and the importance of COVID-19 vaccination on the course of multiple sclerosis (MS).

The 8-year single-center retrospective cohort study compared treatment changes and infection incidence in 115 MS patients before and during the COVID-19 pandemic, as well as COVID-19 incidence and severity before and after COVID-19 vaccination. A multivariate approach assessed the effects of specific factors (age, sex, disease duration, prognostic profile, disease activity before the pandemic, DMTs, and infections) on the course of MS.

Relapse activity was the most common reason for therapy change, with no significant differences (56.52% vs. 61.52%, p = 0.998) before and during the pandemic. There were no differences in the rate of infections before and during the pandemic (67.82% vs. 55.65%, p = 0.16). The severity of COVID-19 courses showed a significant improvement after vaccination (p = 0.047). In the multivariable approach, the only significant factor associated with a higher risk of relapse was disease activity before the pandemic period (OR = 6.80, p = 0.010).

The COVID-19 pandemic did not affect the course of MS in long-term follow-up. The only factor associated with relapse activity during the pandemic period was disease activity in the pre-pandemic period. COVID-19 vaccination may be an essential tool in the care of MS patients.