The effect of COVID-19 vaccination on multiple sclerosis activity as reflected by MRI

Introduction: Examining the safety of theBNT162b2 mRNA vaccine in multiple sclerosis (MS) patients remains inconclusive, particularly regarding the potential for disease exacerbations. This study aims to assess the effects of BNT162b2 COVID-19 vaccination on disease activity in MS patients through sequential MRI imaging. Methods: A retrospective study of 84 MS patients from five Israeli hospitals was conducted. MS lesion load was determined from three brain MRI scans, one postvaccination and two prevaccination scans. A post hoc analysis compared subgroups featuring vaccinated and unvaccinated patients respectively, with early onset MS. Results: The cohort included 70 women with early onset (mean age 16.4 ± 0.8 years) and adult onset (mean age 34.9 ± 1.1 years) MS. Among the early onset group, vaccinated patients showed an increased risk of new lesions (p =.00026), while there was no increased risk among adult-onset patients. Additionally, a comparison between early onset vaccinated and nonvaccinated groups revealed a higher risk of increased lesions in the vaccinated group (p =.024). Discussion: Overall, the study suggests that the BNT162b2 vaccine is generally safe in MS patients, with no association found between vaccination and new lesions in most patients. However, close MRI follow-up is recommended for early-onset MS cases to monitor lesion development.