Exploration on the Quadrivalent Influenza Vaccine Immunization Schedule for Children Aged 3-8 Years

NCT ID: NCT06095947

Last Updated: 2025-09-15

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 652 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2021-09-15
• Study Completion Date: 2023-02-28

Brief Summary

The goal of this [To evaluate the immunogenicity and safety of 1 - and 2-dose schedules of quadrivalent influenza vaccine (split virion) in healthy people with and without immunization history.] is to [aged 3-8 years] in [Healthy people]. The main question[s] it aims to answer are: • [To evaluate the immunogenicity of a two-dose schedule of quadrivalent influenza vaccine (quadrivalent influenza vaccine) in healthy population aged 3-8 years with or without vaccination history.]

•[ To evaluate whether antibody levels are different 30 days after one dose of quadrivalent influenza vaccine versus two doses of quadrivalent influenza vaccine in healthy people aged 3-8 years with or without vaccination history.]

Detailed Description

An open clinical trial design was used. A total of 652 healthy children aged 3-8 years, 326 with vaccination history and 326 without vaccination history, were selected to receive two doses of normal commercially available quadrivalent influenza vaccine according to a 0 -, 30-day schedule.

Immunogenicity: blood samples were collected for HI antibody detection before the first dose of influenza vaccine (before immunization), 30 days after the first dose of influenza vaccine (before the second dose of influenza vaccine) and 30 days after the second dose of influenza vaccine.

Adverse events (AE) were observed 30 minutes, 0-7 days and 8-30 days after each dose of vaccination by active follow-up combined with guardian reports. Occurrence of SAEs between 31 and 180 days after the second dose of vaccine.

Criteria for evaluation of immunogenicity According to the European Union seasonal influenza evaluation criteria, if the HI antibody seroconversion rate of each subtype of influenza virus was ≥40%, the HI antibody positive rate was ≥70%, and the GMI of each subtype of influenza virus was ≥2.5 times 30 days after any dose of vaccination, the vaccination schedule was considered to have acceptable immunogenicity.

Safety outcome MEASURES The occurrence of adverse reactions/events after each dose of vaccination was observed. The incidence of ① total adverse reactions/events, ② incidence of grade 3 or above adverse reactions/events and SAE, ③ incidence of adverse reactions/events severity classification, ④ incidence of adverse reactions/events by type (inoculation site and systemic, SOC, PT) and incidence of adverse reactions/events severity classification were calculated.

Note: Known adverse effects of quadrivalent influenza vaccine that have been identified in previous clinical studies are as follows:

Inoculation site (local) adverse events: pain, induration, swelling, rash, redness, pruritus, cellulitis.

Adverse events at non-inoculated sites (systemic) included fever, diarrhea, constipation, dysphagia, anorexia, vomiting, nausea, myalgia (non-inoculated sites), arthralgia, headache, cough, dyspnea, pruritus at non-inoculated sites (without skin lesions), mucocutaneous abnormalities, irritation/inhibition, acute anaphylaxis, and fatigue/fatigue.

Conditions

GCP

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

There was an immunological history group

l Children who have received two or more doses of influenza vaccine (4 weeks apart) before the influenza season (2 doses of influenza vaccine do not need to be administered in the same epidemic season or consecutive epidemic season, and can be interpreted as children who have received two or more cumulative doses).

Influenza Vaccine (Split Virion), Inactivated, Quadrivalent

Intervention Type: BIOLOGICAL

A total of 652326 healthy children with immunization history and no immunization history aged 3-8 years who met the program requirements received two doses of normally commercially available quadrivalent influenza vaccine according to the 0,30-day procedure.

There was no immunological history group

l Children who have not received or previously received \<2 doses of influenza vaccine before the epidemic season.

Influenza Vaccine (Split Virion), Inactivated, Quadrivalent

Intervention Type: BIOLOGICAL

A total of 652326 healthy children with immunization history and no immunization history aged 3-8 years who met the program requirements received two doses of normally commercially available quadrivalent influenza vaccine according to the 0,30-day procedure.

Interventions

Influenza Vaccine (Split Virion), Inactivated, Quadrivalent

A total of 652326 healthy children with immunization history and no immunization history aged 3-8 years who met the program requirements received two doses of normally commercially available quadrivalent influenza vaccine according to the 0,30-day procedure.

Intervention Type: BIOLOGICAL

Eligibility Criteria

Inclusion Criteria

• 3-8 years old;
• The legal guardian / authorized agent gives the informed consent and voluntarily signs the informed consent to comply with the requirements of the clinical trial protocol;
• Medical history, physical examination and clinical diagnosis, who to the immunization of this product.
• children who have received two or more doses of influenza vaccine (4 weeks apart) before the season of this influenza epidemic (2 doses of influenza vaccine do not need to be vaccinated in the same epidemic season or consecutive epidemic season, but can be interpreted as children who have received two or more cumulative shots).

History of l No immunization: children who had not been vaccinated or had previously received <2 doses of influenza vaccine before the influenza season.

• Other reasons for exclusion as considered by the investigator.

Exclusion Criteria

• Any influenza vaccine (registered or research) within 6 months prior to enrollment; or planned for use during the study period;
• Use of immunoglobulin and / or any blood products within 3 months prior to enrollment; or planned for use during the study (before blood sampling);
• Patients with a history of Guillain-Barre syndrome; l Acute disease, severe chronic disease, acute onset of chronic disease, cold;
• Uncontrolled epilepsy;
• Has been diagnosed with congenital or acquired immunodeficiency, HIV infection, lymphoma, leukemia, or other autoimmune diseases;
• those receiving immune booster or inhibitor treatment within 3 months (continuous oral or drip for more than 14 days);
• History of abnormal coagulation function (such as lack of coagulation factors, coagulation disease);
• Primary and secondary impaired immunity (history of thyroid, pancreas, liver and spleen resection);
• A history of severe allergic reactions to vaccination;
• live attenuated vaccine within 14 days before vaccination and other vaccines within 7 days before vaccination;
• Is in or recently planning to participate in other clinical trials;
• Other conditions judged by the investigator as not suitable for participation in this clinical trial.

• Patients with severe allergic reactions after the previous dose of vaccination;

• Minimum Eligible Age: 3 Years
• Maximum Eligible Age: 8 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Hualan Biological Bacterin Co. Ltd.

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Kou Zengqiang

Jinan, Shandong, China

Countries

China

Other Identifiers

HL-SJLG-2021-Ⅳ-02

Identifier Type: -

Identifier Source: org_study_id