A STUDY OF A RSV VACCINE WHEN GIVEN TOGETHER WITH TDAP IN HEALTHY NONPREGNANT WOMEN AGED BETWEEN 18 TO 49 YEARS

This phase 2b study will evaluate safety, tolerability, and immunogenicity of an RSV vaccine when given together with Tdap in approximately 710 healthy nonpregnant women 18 through 49 years of age. This study will evaluate non-inferiority of RSV vaccine when given with Tdap and vice-versa.

This Phase 2b study will evaluate safety, tolerability, and immunogenicity of an RSV vaccine when given together with Tdap in approximately 710 healthy nonpregnant women 18 through 49 years of age.

The participants will be equally split into 5 treatment groups: One of a possible two dose levels of RSV vaccine (the higher dose level will be formulated with an aluminum hydroxide adjuvant) with either the Tdap or Placebo, or a Tdap and placebo combination.

This study will evaluate non-inferiority of the Tdap when co-administered with RSV vaccine candidate and vice-versa by measuring participants' immune response through appropriate antibody and component levels 1 month after vaccination.

Eligibility Criteria:
Inclusion Criteria:

* Healthy women ≥18 and ≤49 years of age who are of childbearing potential or not of childbearing potential. (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.)
* Willing and able to comply with all scheduled visits, treatment plan, lifestyle considerations, and other study procedures.
* Expected to be available for the duration of the study and can be contacted by telephone during study participation.
* Body mass index (BMI) of \<40 kg/m2 at the time of the consent.
* Capable of giving signed informed consent as which includes compliance with the requirements and restrictions listed within.

Exclusion Criteria:

* 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 participant inappropriate for entry into this study.
* Known infection with human immunodeficiency virus (HIV), hepatitis C virus (HCV), or hepatitis B virus (HBV).
* History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the vaccines being administered in the study.
* History of latex allergy.
* Immunocompromised participants with known or suspected immunodeficiency, as determined by history, laboratory tests, and/or physical examination.
* Any contraindication to Tdap (including encephalopathies).
* 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).
* Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection.
* Women who are pregnant or breastfeeding.
* Previous vaccination with any licensed or investigational RSV vaccine, or planned receipt of nonstudy RSV vaccine throughout the study.
* 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, participants should not be enrolled into the study until corticosteroid therapy has been discontinued for at least 28 days before investigational product administration. Inhaled/nebulized, intra-articular, intrabursal, or topical (skin or eyes) corticosteroids are permitted.
* Receipt of blood/plasma products or immunoglobulin within 60 days before investigational product administration or planned receipt throughout the study.
* Current alcohol abuse, marijuana abuse, or illicit drug use.
* Vaccination within 5 years with DTaP or tetanus and diphtheria toxoids adsorbed (Td) vaccine before investigational product administration.
* 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 Pfizer employees, including their family members, directly involved in the conduct of the study.
* Current febrile illness (oral temperature ≥38.0C \[≥100.4F\]) or other acute illness within 48 hours before investigational product administration.
* Receipt of any inactivated vaccine within 14 days and any live vaccine within 28 days before or anticipated receipt of any vaccine within the 14 days after investigational product administration.
* Receipt of short-term (\<14 days) systemic corticosteroids. Investigational product administration should be delayed until systemic corticosteroid use has been discontinued for at least 28 days. Inhaled/nebulized, intra-articular, intrabursal, or topical (skin or eyes) corticosteroids do not require temporary delay of investigational product administration.