Phase I Clinical Trial of Quadrivalent Influenza Virus Split Vaccine

This is a randomized, blinded, active-controlled phase I clinical trial to evaluate the safety and preliminary immunogenicity of the Quadrivalent Influenza Virus Split Vaccine (QIV) in subjects (aged 3 years and above). Primary endpoints are the occurrence of safety events after vaccination including the incidence of adverse events/adverse reactions within 30 minutes/7 days/30 days after immunization, as well as the incidence of serious adverse events/adverse relations within 6 months which will be defined as the secondary safety endpoint. Besides, the secondary immunogenicity endpoints are the geometric mean titers, geometric mean fold increases, seropositive rates, and seroconversion rates of anti-influenza virus HI antibodies for all types 30 days after immunization.

This is a randomized, blinded, active-controlled phase I clinical trial to evaluate the safety and preliminary immunogenicity in 180 subjects (aged 3 years and above). Then 40 adults (aged 18-59 years), 40 elders (aged 60 years and above), 40 adolescents (aged 9-17 years), and 60 children (aged 3-8 years) are eligible for enrollment after assessing through the medical history and physical examination according to the principle of age escalating from adults to children. 40 adults in the first stage of the study will be randomly assigned to the vaccine and control cohort in a ratio of 1:1, that is, 20 subjects in such group will be injected with the experimental or active-controlled vaccine. The principal investigator and sponsors will conduct the safety evaluation by assessing the preliminary safety data within 7 days after the injection. If the results meet the criterion, the study will continue to the second stage after putting the record to IRB. 40 elders and 40 adolescents in the second stage of the study will be randomly assigned to the vaccine and control cohort in a ratio of 1:1, respectively, that is 40 subjects in such group will be injected with the experimental or active-controlled vaccine. The principal investigator and sponsors will conduct the safety evaluation by assessing the preliminary safety data within 7 days after the injection. If the results meet the criterion, the study will continue to the third stage after putting the record to IRB. 60 children in the third stage of the study will be randomly assigned to the 2-dose vaccine, 1-dose vaccine, and control group in a ratio of 1:1:1, that is 20 subjects in the 2-dose vaccine cohort will receive 2 doses of experimental vaccines in a 0,28 program, and 20 subjects in the 1-dose vaccine or control cohort will receive 1 dose of experimental or active-controlled vaccine. The principal investigator and sponsors will conduct the safety evaluation by assessing the preliminary safety data within 7 days after the injection. If the results meet the criterion, the study will continue to complete the second administration in the 2-dose vaccine cohort after putting the record to IRB. The duration of intervention is no more than 1 month. With the 6-month safety monitoring after administration, the duration of the study is no more than 7 months. For safety assessment, the observation and evaluation of adverse events from Day 0 to Day 30 after each dose will be conducted by diary/contact cards and investigators' phone calls. Besides, the observation and evaluation of serious adverse events up to 6 months after vaccination will be conducted by active reports by subjects' legal guardians, or investigators' phone calls as well as face-to-face visits. Meanwhile, subjects will be observed at the site for at least 30 minutes after each dose. For laboratory examination, blood biochemistry, blood routine, and urine routine tests or urine pregnancy tests (if applicable) will be performed on Day 0 before vaccination as well as Day 4 after administration for all subjects. For immunogenicity assessment, antibodies against all vaccine-related types of Influenza virus will be assessed in all subjects before vaccination and 30 days after full vaccination.