Clinical trials

This is a prospective, open-label, parallel time-cohort study designed to characterize the humoral and cellular immune responses induced by a subunit influenza vaccine (manufactured by Ab\&B Bio-tech Co., Ltd.JS) in healthy adults within one month after vaccination. Eligible participants will receive a single intramuscular dose and will be assigned in parallel to one of two blood-sampling schedules to capture the kinetic profile of the immune response: Group A (pre-vaccination, Day 5, and Day 14 post-vaccination) and Group B (pre-vaccination, Day 7, and Day 21 post-vaccination). Hemagglutination inhibition (HI) antibody titers will be measured to assess humoral immunity, while circulating CD4⁺ and CD8⁺ T-cell levels will be analyzed to evaluate cellular immunity. The occurrence of adverse events（AEs) and serious adverse events(SAEs) within 28 days post-vaccination will be recorded.

The primary objective of the phase I trial is to evaluate the safety and tolerability of different doses of the recombinant respiratory syncytial virus vaccine (CHO cell) (Adjuvanted) in adults aged 18 years and older, with the secondary objective being to assess its immunogenicity. The primary objectives of the phase II trial are to evaluate the immunogenicity and safety of the recombinant respiratory syncytial virus vaccine (CHO cell) (Adjuvanted) with different adjuvant ratios in adults aged 60 years and older, with the secondary objective being to evaluate the persistence of immune responses.