A Study to Assess Safety, Tolerability and Immunogenicity of RSVpreF From Multidose Vials in Healthy Female Adults.

Inclusion Criteria:

1. Healthy nonpregnant, nonbreastfeeding females 18 through 49 years of age at Visit 1 (Day 1).

2. Willing and able to comply with all scheduled visits, investigational plan,lifestyle considerations, and other study procedures.

3. Available for the duration of the study and can be contacted by telephone duringstudy participation.

4. Capable of giving signed informed consent as described in the protocol whichincludes compliance with the requirements and restrictions listed in the ICD and inthe protocol.

Exclusion Criteria:

1. Any medical or psychiatric condition including recent (within the past year) oractive suicidal ideation/behavior or laboratory abnormality that may increase therisk of study participation or, in the investigator's judgment, make the participantinappropriate for the study.

2. History of severe adverse reaction associated with a vaccine and/or severe allergicreaction (eg, anaphylaxis) to any component of the vaccines being administered inthe study.

3. Immunocompromised participants with known or suspected immunodeficiency, asdetermined by history, laboratory tests, and/or physical examination.

4. History or active autoimmune disease, including but not limited to systemic orcutaneous lupus erythematosus, autoimmune arthritis/rheumatoid arthritis,Guillain-Barré syndrome, multiple sclerosis, Sjögren's syndrome, idiopathicthrombocytopenia purpura, glomerulonephritis, autoimmune thyroiditis, giant cellarteritis (temporal arteritis), psoriasis, and insulin-dependent diabetes mellitus (type 1).

5. Bleeding diathesis or any condition that would, in the opinion of the investigator,contraindicate intramuscular injection.

6. Previous vaccination with any licensed or investigational RSV vaccine, or plannedreceipt of a nonstudy RSV vaccine throughout the study.

7. Receipt of chronic systemic treatment with immunosuppressant medications (includingcytotoxic agents or systemic corticosteroids), or radiotherapy, within 60 daysbefore enrollment through conclusion of the study.

8. Receipt of blood/plasma products or immunoglobulin within 60 days before studyintervention administration or planned receipt throughout the study.

9. Current alcohol abuse or illicit drug use.

10. Individuals who are pregnant or breastfeeding.

11. Participation in other studies involving an investigational product within 28 daysprior to study entry and/or during study participation. Participation in purelyobservational studies is acceptable.

12. Investigator site staff directly involved in the conduct of the study and theirfamily members, site staff otherwise supervised by the investigator, and sponsor andsponsor delegate employees directly involved in the conduct of the study and theirfamily members.