The study was terminated during the EC submission process prior to the enrolment

This phase 1 study in Australia will evaluate the safety, reactogenicity and immunogenicity of the Bivalent Recombinant Respiratory Syncytial Virus (RSV) Vaccine (CHO Cell) (SCB-1019T) in children 2-<6 years of age.

This Phase 1 randomized, placebo-controlled, observer-blind study will evaluate the safety, reactogenicity and immunogenicity of different formulations of SCB-1019T vaccine in children 2-<6 years of age. A placebo is used as a control in the study because there is no licensed RSV comparator vaccine available for young children globally.

Inclusion Criteria:

• Male and female participants 2 to <6 years of age at Visit 1. • Parents/guardians of participants willing and able to provide written informed consent and comply with study requirements, including all scheduled visits, vaccination, laboratory tests, and other study procedures. • Healthy participants as determined by medical history, physical examination, and clinical judgment of the investigator.

For full inclusion criteria, please refer to full protocol.

Exclusion Criteria:

• Acute disease or fever (≥38°C) at time of vaccination. For participants with minor illness and/or fever at the time of vaccination, Visit 1 may be rescheduled.
• Evidence of chronic diseases including hepatitis, bleeding disorders, metabolic diseases, autoimmune diseases, neurological conditions that impair respiratory functions, genetic disorders that increase the risk of severe respiratory diseases, major congenital malformations, cardiac and lung diseases or reactive airway diseases.

For full Exclusion criteria, please refer to full protocol