Safety Study of Oral BTA9881 to Treat RSV Infection

Inclusion Criteria: 1. Healthy male and female subjects \>=18 and \<=45 years of age. 2. Individuals who have freely given Informed Consent in writing. 3. Male subjects should use appropriate contraception (e.g. condoms) during the time interval between dosing until three months after dosing. Female subjects must be surgically sterile or post-menopausal (defined as at least two years post cessation of menses and/or follicle-stimulating hormone (FSH) \>18 mIU/mL and serum oestradiol \<110 pmol/L), or must agree to use two forms of the following contraception: oral contraceptives, or other forms of hormonal birth control including hormonal vaginal rings or transdermal patches, intra-uterine devices, condoms, and spermicide during the time interval between dosing until three months after dosing. Female subjects must also be non-lactating and have a negative serum pregnancy test at screening and at baseline. 4. Able to perform nasal wash procedure. 5. Normotensive (systolic BP ≤ 140 mm Hg and diastolic BP ≤ 90 mm Hg). 6. No abnormal finding of clinical relevance at the screening examination that the Investigator considers might interfere with the objectives of this clinical trial. 7. No clinically relevant abnormality in the ECG; QTc \<430 ms (males) or \<450 ms (females). 8. Healthy based on medical history, physical examination, 12-lead ECG and clinical laboratory tests, and with no disease that the Investigator regards as clinically relevant. 9. Negative results in Human Immunodeficiency Virus (HIV) antibody, Hepatitis B surface antigen (HBsAg) and Hepatitis C antibody tests. 10. Willingness to abstain from alcohol and caffeine-containing food and beverages for 48 hours prior to dosing and for the duration of the clinical trial. Exclusion Criteria: 1. Use of any prescription medication (other than allowable oral contraceptives and implanted hormonal contraceptives) during the 14 days prior to dosing. 2. Use of any non-prescription ('over the counter') product, including herbal products, diet aids, hormone supplements, etc., within 14 days prior to dosing. 3. Intake of any investigational drug within 3 months prior to dosing. 4. History or clinical evidence of significant cardiovascular disease (including risk factors for cardiac arrhythmias) or a previous history of any cardiovascular condition that, in the opinion of the investigator, would interfere with the conduct of the trial. 5. History or clinical evidence of significant cerebrovascular, cardiovascular, gastrointestinal, or haematological disease, or myocardial infarction, or a previous history of any other serious underlying disease (including immunocompromised subjects and/or neutropenic subjects) that, in the opinion of the investigator would interfere with the conduct of the clinical trial. 6. History or clinical evidence of significant respiratory disease (including asthma, chronic obstructive pulmonary disease, cystic fibrosis and/or recurrent lower respiratory tract infection), or upper respiratory tract infection within the last month or lower respiratory tract infection within the last three months. 7. History or clinical evidence of renal disease (including renovascular occlusive disease), nephrectomy and/or renal transplant, and/or previous clinically significant laboratory abnormalities of renal function parameters. All subjects with serum creatinine or proteinuria outside the normal laboratory reference range at screening and baseline that are regarded by the Investigator as clinically significant. 8. History or clinical evidence of hepatic disease and/or previous clinically significant laboratory abnormalities of liver function parameters. All subjects with bilirubin, gamma glutamyl transferase (GGT), alanine transaminase (ALT), and aspartate transaminase (AST) outside the normal laboratory reference range at screening and baseline, that are regarded by the Investigator as clinically significant. Subjects known to have experienced elevated liver enzyme values in previous clinical studies will also be excluded. 9. History or clinical evidence of adrenal disease (including Cushing's Syndrome or Addison's disease) or thyroid disease (including hyper or hypothyroidism), and/or previous clinically significant laboratory abnormalities of adrenal or thyroid function parameters. All subjects with thyroid function (TSH, FT4, FT3) outside the normal laboratory reference range at baseline and regarded by the Investigator as clinically significant. 10. Psychiatric or emotional problems that would invalidate the giving of Informed Consent or limit the ability of the subject to comply with clinical trial requirements. 11. Body Mass Index (BMI) ≤18.5 kg/m2 or \>=30.0 kg/m2. 12. History of alcohol and/or drug abuse within 1 year prior to screening (verified by drug screening). 13. Receipt of blood or blood products, or loss of 450 mL or more of blood, during the last three months prior to dosing. 14. Unwillingness or inability to provide Informed Consent or to participate satisfactorily for the entire clinical trial period. 15. Subjects who smoke or have been non-smokers for less than 3 months prior to dosing. 16. Subjects who were previously enrolled in this clinical trial. 17. Poor veins, or fear of venipuncture or sight of blood, or known allergy or hypersensitivity to lidocaine.