This is a two cohort, multicenter, open-label, prospective study of 40 (optionally up to 60) patients with relapsing multiple sclerosis (RMS) planning to undergo a SARS-CoV-2 mRNA vaccination (initial vaccinations or booster vaccines) as part of clinical routine. The maximal duration of the study for an individual patient is 22 months.~The first cohort will be RMS patients receiving SARS-CoV-2 mRNA vaccine (initial vaccinations or booster vaccines) as part of clinical routine prior to starting ofatumumab treatment.~The second cohort will be participants receiving SARS-CoV-2 mRNA vaccine (initial vaccinations or booster vaccines) as part of clinical routine while already stable on ofatumumab treatment for at least 4 weeks (since first dose).~Development of SARS-CoV-2 specific T-cells and functional anti-SARS-CoV-2 antibodies will be investigated for up to 18 months after the participants' vaccination.
This study aims to understand whether patients with MS can mount an immune response to SARS-CoV-2 mRNA vaccines (initial vaccinations or booster vaccines) when vaccinated either before initiation of ofatumumab treatment or at least 4 weeks after commencing ofatumumab treatment.