We investigate the effects of B cell depletion therapy using ocrelizumab on the immune system and use this information in the vaccination strategy against COVID-19 for ocrelizumab-treated individuals with MS.

Understanding how B cell destruction with ocrelizumab affects the immune system in the treatment of MS. The destruction of B cells, a subset of immune cells, shows high efficacy in MS treatment. The B cell depleting agent ocrelizumab has been approved for the treatment of both relapsing-remitting and primary progressive MS. However, its effects on the immune system remain largely unknown. Therefore, we aim to identify immunological changes after ocrelizumab treatment in individuals with MS and its implications for COVID-19 management. To do this, we will analyse blood samples of individuals with MS before, after 6 and 12 months of ocrelizumab treatment and after treatment interruption related to COVID-19. This project will increase insight into the working mechanism of ocrelizumab and will be crucial in designing anti-SARS-CoV-2 vaccination strategies for ocrelizumab-treated individuals with MS.