['respiratory syncytial virus infections']
['rv521', 'placebo']

        Inclusion Criteria:

          -  Age 18 to 45 years, inclusive

          -  In good health with no history of major medical conditions

          -  A total body weight ≥ 50 kg and a body mass index (BMI) of >/=18kg/m2 and </=30kg/m2

        Exclusion Criteria:

          -  Evidence of any clinically significant or currently active major medical condition

          -  Positive for Human Immunodeficiency Virus, active Hepatitis A, B or C test

          -  Significant nose or nasopharynx abnormalities

          -  Abnormal lung function

          -  History or currently active symptoms suggestive of upper or lower respiratory tract
             infection
      