A Study to Assess the Safety, Tolerability, and Immunogenicity of RSVpreF in Older Adults in Korea

Inclusion Criteria

• Participants 60 years of age or older at Visit 1
• Male participants able to father children must agree to use a highly effective method of contraception from the time of informed consent through at least 28 days after study intervention administration
• Female participants must not be of childbearing potential
• Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study.

Healthy participants with preexisting stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included.

• Participants who are willing and able to comply with all scheduled visits, investigational plan, laboratory tests, frequent symptom assessment by mobile device application (e-diary), and other study procedures.
• Participants who are ambulatory and live in the community, or in assisted-living or long-term care residential facilities that provide minimal assistance, such that the participant is primarily responsible for self-care and activities of daily living (ADL).
• Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent document (ICD) and the protocol.

Exclusion Criteria

• A confirmed diagnosis of RSV infection ≤180 days before study intervention administration.
• Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular (IM) injection.
• Prior history of any subtype of Guillain-Barré syndrome (GBS) of any etiology.
• History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s) or any related vaccine.
• Serious chronic disorder, including metastatic malignancy, end-stage renal disease with or without dialysis, clinically unstable cardiac disease, or any other disorder that, in the investigator's opinion, excludes the participant from participating in the study.
• Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
• Any medical or psychiatric condition, including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality, that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• Individuals who receive chronic systemic treatment with immunosuppressive therapy (other than systemic corticosteroids meeting the criteria noted below), including cytotoxic agents, immunosuppressive monoclonal antibodies, or radiotherapy, eg, for cancer or an autoimmune disease, from 60 days before study intervention administration or planned receipt throughout the study.
• Receipt of systemic corticosteroids (≥20 mg/day of prednisone or equivalent) for

≥14 days from 28 days before study intervention.

• Inhaled/nebulized, intra articular, intrabursal, or topical (skin or eyes) corticosteroids are permitted.
• Receipt of blood/plasma products or immunoglobulin within 60 days before study intervention administration.
• Previous vaccination with any licensed or investigational RSV vaccine, or planned receipt throughout the study.
• Previous administration with an investigational product (drug or vaccine) within 6 months prior to study intervention administration. Participation in other studies involving an investigational product (drug or vaccine) at any time during participation in this study.
• Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family mem