Inclusion Criteria:  For MS Patients:  Diagnosis of MS Treatment with one of the four DMTs (Kesimpta (ofatumumab), Ocrevus (ocrelizumab), Gilenya (fingolimod), Mayzent (siponimod)) for at least 3 months prior to first SARS-CoV2 vaccine dose SARS-CoV2 vaccine regimen complete within the past 2-3 or 5-6 months (either Moderna® or Pfizer-BioNTech® mRNA vaccines) Age 18-65, inclusive  For Health Controls:  1. Age 18-65, inclusive  Exclusion Criteria:  For MS Patients:  1. Prior known COVID-19 infection  For Health Controls:  Prior known COVID-19 infection major autoimmune disorders or current treatment with immunosuppressive or immunomodulatory drugs