Vaccination Response in Tecfidera-Treated Versus Interferon-Treated Participants With Relapsing Forms of Multiple Sclerosis.

Primary objective is to evaluate the immune response to vaccination with tetanus diphtheria toxoids vaccine (Td) in participants with relapsing forms of Multiple Sclerosis (MS) who have been treated with Tecfidera (BG00012) versus those treated with non pegylated interferon (IFN). Secondary objective is to evaluate the immune response to vaccination with 23-valent pneumococcal polysaccharide vaccine (PPSV23) \[a mostly T cell-independent humoral response\] and meningococcal polysaccharide diphtheria conjugate vaccine, quadrivalent (MCV4) \[T cell-dependent neoantigen response\].