['respiratory syncytial virus infections']
['placebo (formulation buffer s9b)']

        Inclusion Criteria:

          -  Subjects who, in the opinion of the investigator, can and will comply with the
             requirements of the protocol.

          -  Written informed consent obtained from the subject prior to performance of any study
             specific procedure.

          -  Non-pregnant female between, and including, 18 and 45 years of age at the time of
             study vaccination.

          -  Healthy subjects as established by medical history and clinical examination before
             entering into the study.

          -  Female subjects of non-childbearing potential may be enrolled in the study

               -  Non-childbearing potential is defined as pre-menarche, hysterectomy, ovariectomy
                  or post-menopause.

          -  Female subjects of childbearing potential may be enrolled in the study, if the
             subject:

               -  Has practiced adequate contraception for 30 days prior to study vaccination, and

               -  Has a negative pregnancy test on the day of study vaccination, and

               -  Has agreed to continue adequate contraception up to 90 days after vaccination.

        Exclusion Criteria:

          -  Use of any investigational or non-registered product other than the study vaccines
             within 30 days prior to study vaccination, or planned use during the study period.

          -  Concurrently participating in the active phase of another clinical study, at any time
             during the study period, in which the subject has been or will be exposed to an
             investigational or a non-investigational vaccine/product.

          -  Chronic administration of immunosuppressants or other immune-modifying drugs, as well
             as administration of long-acting immune-modifying drugs, within 6 months prior to
             study vaccination, or planned administration until 90 days post-vaccination. For
             corticosteroids, this will mean prednisone ≥ 10 mg/day, or equivalent. Inhaled and
             topical steroids are allowed.

          -  Administration of immunoglobulins and/or any blood products during the period starting
             3 months before the study vaccination, or planned administration until 90 days
             post-vaccination.

          -  Planned administration/administration of a vaccine not foreseen by the study protocol
             within the period starting 30 days before and ending 30 days after study vaccination,
             with the exception of any licensed influenza vaccine which may be administered ≥ 15
             days before or after study vaccination.

          -  Previous experimental vaccination against RSV.

          -  History of any neurological disorders or seizures.

          -  Family history of congenital or hereditary immunodeficiency.

          -  Any confirmed or suspected immunosuppressive or immunodeficient condition, based on
             medical history and physical examination

          -  History of or current autoimmune disease

          -  Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal
             functional abnormality as determined by physical examination and/or Medical History.

          -  Lymphoproliferative disorder or malignancy within previous 5 years.

          -  History of any reaction or hypersensitivity likely to be exacerbated by any component
             of the study vaccine.

          -  Hypersensitivity to latex.

          -  Any medical condition that in the judgment of the investigator would make
             intramuscular injection unsafe.

          -  Current alcohol and/or drug abuse.

          -  Acute disease and/or fever at the time of enrolment.

               -  Fever is defined as temperature ≥37.5°C for oral, axillary or tympanic route, or
                  ≥ 38.0°C for rectal route.

               -  Subjects with a minor illness without fever may be enrolled at the discretion of
                  the investigator.

               -  For subjects with acute disease and/or fever at the time of enrolment, Visit
                  1/Day 0 will be rescheduled within the allowed recruitment period.

          -  Body mass index (BMI) > 40 kg/m².

          -  Pregnant or lactating female.

          -  Planned move to a location that will prohibit participating in the trial until study
             conclusion.

          -  Any other condition that the investigator judges may interfere with study procedures
             or findings.
      