A Study To Evaluate the Safety of XW001 Inhalation in Children With RSV

Inclusion Criteria: 1. Male or female, 1 to 24 months (inclusive) at screening; 2. Weight: 3-20 kg, inclusive; 3. Positive RSV test within 36 hours before randomization; 4. Symptomatic at screening and randomization, and the onset of RSV symptoms is within 5 days prior to the first dose of XW001; 5. Parents/legal guardians are able to understand the purpose and procedures of the study, and are able to provide informed consent. Exclusion Criteria: 1. Immunocompromised as determined by the investigator; 2. Known to have undergone or planned for bone marrow, stem cells, or other organ transplants, or are currently on immunosuppressive treatment; 3. Positive for HBV, HCV or HIV, or patient \<6 months old whose mother is positive for HIV; 4. History of seizures or epilepsy, including febrile seizure; 5. Known to have received any prohibited medications defined by the protocol within 3 days prior to randomization; 6. History of any surgery within 30 days prior to randomization; 7. Severe dental or facial deformity that will impact on usage of nebulizer; 8. History of receiving measles, mumps, rubella or other vaccines within 7 days prior to screening; 9. Known to have received any investigational medicinal products or devices in the past 30 days; 10. Any other underlying conditions that make the patient unlikely to complete the study in the opinion of the investigator.