Inclusion Criteria  Age 18-55 Diagnosis of multiple sclerosis (as per the revised 2017 criteria) EDSS score of 0-5.5 inclusive Has initiated ocrelizumab or natalizumab at least 6 months prior to study enrollment For women of childbearing potential: agreement to remain abstinent or to use a highly effective (99% efficacy or greater) contraceptive method Individual must be able to provide consent, read/write/comprehend English language or must be able to provide a consistent translator  Exclusion Criteria  Previous infection with COVID-19, confirmed by FDA approved testing Cognitive impairment limiting the ability to consent or complete study procedures Currently pregnant, planning to become pregnant during the study period, or currently breastfeeding Any prior use of immunosuppressive or chemotherapy treatment (including, but not limited to, cladribine, alemtuzumab, mycophenolate mofetil, cyclophosphamide, methotrexate, azathioprine) Prior treatment with a B-cell depleting therapy other than ocrelizumab within 12 months of first on-study infusion excluding standard ocrelizumab pre-treatment therapy Use of systemic corticosteroid therapy within 12 weeks of screening (excluding corticosteroid treatment given concurrently with ocrelizumab) History of allergic reactions to vaccines