A Study to Describe the Safety and Immunogenicity of a RSV Vaccine in Healthy Adults

The study will describe the safety, tolerability, and immunogenicity of up to 6 RSV vaccine
formulations when administered alone or concomitantly with SIIV. Healthy male and female
subjects divided into 2 age groups (18-49 years of age and 50-85 years of age in the sentinel
cohort and 18-49 years of age and 65-85 years of age in the expanded cohort) will be
enrolled. Age groups will run in parallel. Subjects in the sentinel cohort in each age group
will receive one of two RSV vaccine formulations at one of 3 antigen dose levels or placebo.
Subjects in the expanded cohort in each age group will receive one of two RSV vaccine
formulations at one of 3 antigen dose levels with and without SIIV.

Inclusion Criteria:

1. Evidence of a personally signed and dated informed consent document (ICD) indicating
that the subject has been informed of all pertinent aspects of the study.

2. Healthy adults who are determined by medical history, physical examination, and
clinical judgment of the investigator to be eligible for inclusion in the study.

3. Willing and able to comply with scheduled visits, vaccination plan, laboratory tests,
and other study procedures.

4. Male subject who is able to father children and willing to use a highly effective
method of contraception as outlined in this protocol until at least 28 days after the
last dose of investigational product; female subject who is of childbearing potential
and at risk for pregnancy and who is willing to use a highly effective method of
contraception as outlined in this protocol until at least 28 days after the last dose
of investigational product; male subject not able to father children; female subject
not of childbearing potential.

5. Sentinel-cohort subjects only: Male and female adults aged 18 to 85 years at the time
of enrollment (signing of the ICD).

6. Expanded-cohort subjects only: Male and female adults aged 18 to 49 years of age or 65
to 85 years at the time of enrollment (signing of the ICD).

Exclusion Criteria:

1. Sentinel-cohort subjects only: Any screening hematology and/or blood chemistry
laboratory value that meets the definition of a ≥ Grade 1 abnormality.

2. Sentinel-cohort subjects only: Positive test for human immunodeficiency virus (HIV),
hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (HBc Abs), or
hepatitis C virus antibodies (HCV Abs) at the screening visit.

3. Investigator site staff members directly involved in the conduct of the study and
their family members, site staff members otherwise supervised by the investigator, or
subjects who are Pfizer employees, including their family members, directly involved
in the conduct of the study.

4. Participation in other studies involving investigational product within 28 days prior
to study entry and/or during study participation.

5. Known infection with HIV, hepatitis C virus (HCV), or hepatitis B virus (HBV).

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

7. History of severe adverse reaction associated with a vaccine and/or severe allergic
reaction (eg, anaphylaxis) to any component of the investigational product(s).

8. Immunocompromised subjects with known or suspected immunodeficiency, as determined by
history and/or laboratory/physical examination.

9. Subjects who receive treatment with immunosuppressive therapy, including cytotoxic
agents or systemic corticosteroids, eg, for cancer or an autoimmune disease, or
planned receipt throughout the study. If systemic corticosteroids have been
administered short term (<14 days) for treatment of an acute illness, subjects should
not be enrolled into the study until corticosteroid therapy has been discontinued for
at least 28 days before investigational product administration. Intra-articular,
intrabursal, or topical (skin or eyes) corticosteroids are permitted.

10. Subject with a history of autoimmune disease or an active autoimmune disease requiring
therapeutic intervention including but not limited to: systemic or cutaneous lupus
erythematosus, autoimmune arthritis/rheumatoid arthritis, Guillain-Barré syndrome,
multiple sclerosis, Sjögren's syndrome, idiopathic thrombocytopenia purpura,
glomerulonephritis, autoimmune thyroiditis, giant cell arteritis (temporal arteritis),
psoriasis, and insulin-dependent diabetes mellitus (type 1).

11. Receipt of blood/plasma products or immunoglobulin, from 60 days before
investigational product administration or planned receipt throughout the study.

12. Other acute or chronic medical or psychiatric condition including recent (within the
past year) or active suicidal ideation or behavior or laboratory abnormality that may
increase the risk associated with study participation or investigational product
administration or may interfere with the interpretation of study results and, in the
judgment of the investigator, would make the subject inappropriate for entry into this
study.

13. Bleeding diathesis or condition associated with prolonged bleeding that would, in the
opinion of the investigator, contraindicate intramuscular injection.

14. Women who are pregnant or breastfeeding.

15. Expanded-cohort subjects only: Vaccination with any influenza vaccine within 6 months
(182 days) before investigational product administration.

16. Expanded-cohort subjects only: Allergy to egg proteins (egg or egg products) or
chicken proteins.