NCT06824519

Clinical Trials of Quadrivalent Influenza Vaccine

A Randomized, Blinded Phase I./II Clinical Trial to Evaluate the Safety, Tolerability, and Immunogenicity of Influenza Vaccine (Split Virion), Inactivated, Quadrivalent, ZFA02 Adjuvant

• Status: Recruiting
• Phase: Phase 1 / Phase 2
• Study type: Interventional
• Enrollment: 620 (estimated)
• Sponsor: Anhui Zhifei Longcom Biologic Pharmacy Co., Ltd. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

This clinical trial adopts a seamless design of phase I/II, conducted in two stages: phase I and phase II. Phase I is the age/dose ramp up stage, and phase II is the dose expansion stage.The purpose of this clinical trial is to evaluate the safety and tolerability of different doses of Influenza Vaccine (Split Virion), Inactivated, Quadrivalent, ZFA02 Adjuvant，explore the immunogenicity of the vaccine, and determine the appropriate dose for later clinical trials of this product.

Detailed description

Overall design: Adopting a randomized, blinded research design. This experiment adopts a seamless connection design of Phase I/II, conducted in two stages: Phase I and Phase II. Phase I is the age/dose escalation stage, and Phase II is the dose extension stage. Age/dose escalation stage: A randomized, blinded, placebo-controlled study design was used. 120 subjects were enrolled in the study, in order of age from 18 to 49 years old to 50 years old and above, from low dose to high dose. They were divided into four cohorts, with 30 subjects in each cohort (including 20 who received high-dose or low-dose experimental vaccines and 10 who received placebo). The first 6 subjects in each cohort were assigned to be sentinel group, and the researchers reviewed the safety data of the sentinel group within 7 days after vaccination. After confirming safety (not meeting the criteria for suspending/terminating the trial), the remaining 24 subjects in the cohort were enrolled. Dose expansion stage: A randomized, blinded, positive controlled study design was used. 500 subjects were enrolled, divided into two age groups: 18-49 years old and 50 years old and above. 250 subjects were enrolled in each age group and randomly divided into low-dose group, high-dose group, and positive control group according to a 2:2:1 ratio. The proportion of people aged 60 and above in the population aged 50 and above shall not be less than 80%, and the proportion of people aged 70 and above shall not be less than 30%.

Conditions

• Influenza, Human

Interventions

Type	Name	Description
BIOLOGICAL	Influenza Vaccine (Split Virion), Inactivated, Quadrivalent, ZFA02 Adjuvant (low dose)	Inject 1 dose of low-dose vaccine
BIOLOGICAL	Influenza Vaccine (Split Virion), Inactivated, Quadrivalent, ZFA02 Adjuvant placebo (low dose)	Inject 1 dose of low-dose placebo
BIOLOGICAL	Influenza Vaccine (Split Virion), Inactivated, Quadrivalent, ZFA02 Adjuvant (high dose)	Inject 1 dose of high-dose vaccine
BIOLOGICAL	Influenza Vaccine (Split Virion), Inactivated, Quadrivalent, ZFA02 Adjuvant placebo (high dose)	Inject 1 dose of high-dose placebo
BIOLOGICAL	Influenza Vaccine (Split Virion), Inactivated, Quadrivalent	Inject 1 dose of positive control vaccine

Timeline

• Start date: 2025-05-08
• Primary completion: 2025-08-05
• Completion: 2026-09-01
• First posted: 2025-02-13
• Last updated: 2025-11-20

Locations

1 site across 1 country: China