A Phase 1 Study to Evaluate the Safety, Reactogenicity and Immunogenicity of YKYY025 Injection
Male or female participants aged ≥18 to 49 years of age (Part 1) or
Can understand the study procedures, voluntarily sign the informed consent form after informed consent.
Able and willing to complete the study procedures during the entire study Follow-up period.
Body temperature < 37.0°C (Axillary temperature) on the day of enrollment (before vaccination).
Previously received RSV vaccine or have participated or are currently participating in RSV vaccine clinical trials and have received the trial vaccine.
A history of confirmed RSV infection or respiratory diseases related to RSV infection within 6 months prior to vaccination.
Long term (defined as 14 days or more) treatment with immunosuppressants or other immunomodulatory drugs within 6 months prior to vaccination, or planned to receive such treatment within 30 days after vaccination, such as long-term use of systemic corticosteroids (continuous use for 2 weeks or more, dose ≥ 20mg/day prednisone or equivalent prednisone dose, excluding topical medications such as ointments, eye drops, inhalants, or nasal sprays);
Received immunoglobulin and/or any blood products （such as blood, plasma） within 4 months of vaccination, or planning to receive during the study.