Safety Study to Evaluate Immune Response of Vaccines in Participants With Relapsing Forms of Multiple Sclerosis Who Receive Ozanimod Compared to Non-Pegylated Interferon (IFN)-β or No Disease Modifying Therapy

Inclusion Criteria:

Participant has a diagnosis of multiple sclerosis (MS) according to the 2017 revision of the McDonald diagnostic criteria and has relapsing forms of multiple sclerosis (RMS): relapsing-remitting MS (RRMS) or secondary progressive MS with active disease based on recent clinical relapse or MRI lesion activity.

Exclusion Criteria:

1. Participant has history of cancer, including solid tumors and hematological except for basal cell cancer of the skin and carcinoma in situ of the cervix, which are exclusionary if they have not been excised and resolved.
2. Participant has a history of or currently active primary or secondary immunodeficiency.
3. Participant has severely compromised cardiac or pulmonary function for which a systemic hypersensitivity reaction to any of the vaccines would pose a significant risk.
4. Participant has received the seasonal influenza vaccine for the 2021/2022 influenza season prior to Day 1, or history of influenza vaccine for the 2020/2021 influenza season within 6 months prior to Day 1.

Participant has previous treatment with one of the following medications or interventions within the corresponding timeframe described as follows:

1. Any systemic immunosuppressive treatments with potential overlapping effects with the baseline of this study. Corticosteroids that are by non-systemic routes (e.g., topical, inhaled, intra-articular) are allowed.
2. History of treatment with IV immunoglobulin (IVIg) or plasmapheresis within 4 weeks prior to Day 1.