A Clinical Trial of an Inactivated Quadrivalent Influenza Vaccine in Chinese Children Aged 3 to 8 Years

Study Overview
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Brief Summary
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Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. For those aged 6 months through 8 years who have previously received ≥2 total doses of trivalent or quadrivalent influenza vaccine ≥4 weeks apart, they require only 1 dose of influenza vaccine. For those who have not previously received ≥2 doses of trivalent or quadrivalent influenza vaccine, they require 2 dose of influenza vaccine. but the evidence on how to select vaccine doses for quadrivalent influenza vaccine is limited in China. The study is a prospective, open-label comparison of the immunogenicity and reactogenicity of 1 versus 2 doses of an inactivated quadrivalent influenza vaccine in subjects of 3-8 years old with different history of influenza vaccination.

Detailed Description
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Subjects receive 2 dosed of quadrivalent influenza vaccine 4 weeks apart. Blood samples were obtained from children at 3 time points-before receipt of dose 1, 4 weeks after receipt of dose 1 and before dose 2, and 4 weeks after dose 2. Hemagglutination inhibition (HAI) antibody titers to the A/H3N2, A/H1N1, and B antigens included in the vaccine were measured at each time point

Official Title
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A Clinical Trial to Assess Immunogencity and Safety of 2 Doses of an Inactivated Quadrivalent Influenza Vaccine in Chinese Children Aged 3 to 8 Years

Conditions
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Influenza

Intervention / Treatment
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* Biological: Quadrivalent influenza vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 3-8 years old Healthy subjects judged from medical history and clinical examination Subjects themselves or their guardians able to understand and sign the informed consent Subjects themselves or their guardians can and will comply with the requirements of the protocol Subjects have received ≥2 doses of trivalent or quadrivalent infuenza vaccine before enrollment (Doses need not have been received during same or consecutive seasons); Subjects have not received infuenza vaccine before enrollment Subjects with temperature <=37.0°C on axillary setting Exclusion Criteria: Subject who has a medical or family history of any of the following: allergic history, seizure, epilepsy, brain or mental disease Subject who is allergic to any ingredient of the vaccine Subject with damaged or low immune function which has already been known Subject with acute febrile illness or infectious disease Major congenital defects or serious chronic illness, including perinatal brain damage Thrombocytopenia, blood coagulation disorder or bleeding difficulties with intramuscular injection Subject who has serious allergic history Subject who developed guillain-Barre syndrome post influenza vaccination Any prior administration of immunodepressant or corticosteroids in last 6 months Any prior administration of influenza vaccine in last 6 month Any prior administration of blood products in last 3 months Any prior administration of other research medicine/vaccine in last 30 days Any prior administration of any attenuated live vaccine in last 14 days Any prior administration of subunit or inactivated vaccines in last 7 days, such as pneumococcal vaccine Any medical, psychological, social or other condition judged by investigator, that may interfere subject's compliance with the protocol or signature on informed consent for subject's guardian

Ages Eligible for Study
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Minimum Age: 3 Years
Maximum Age: 8 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Interventional Model Description: Subjects received 2 doses of an inactivated quadrivalent influenza vaccine, 4 weeks apart. Blood samples were obtained from children at 3 time points-before receipt of dose 1, 4 weeks after receipt of dose 1 and before dose 2, and 4 weeks after dose 2.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Quadrivalent influenza vaccine<br>Subjects received 2 doses of 0.5 mL of quadrivalent influenza vaccine, 4 weeks apart. Each 0.5-ml dose contained 15 μg of hemagglutinin per strain. | Biological: Quadrivalent influenza vaccine<br>* Subjects receive two doses of quadrivalent influenza vaccine administered 4 weeks apart by intramuscular injection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the 95% confidence interval (CI) lower limit for Seroconversion Rate (SCR) of Hemagglutination inhibition (HAI) antibodies against each virus strain after 2nd vaccination ≥40% | The lowest dilution used in the assay is 1/10. Seroconversion was defined as either a pre-vaccination HAI titer < 1:10 and a post-vaccination titer ≥1:40 or a pre-vaccination titer ≥1:10 and ≥ four-fold increase in post-vaccination titer. | day 28 after dose 2 | 
| Number of participants with Adverse Reactions (ARs) | Frequency and severity of ARs for 28 days after each vaccination | 28 days after each vaccination | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the 95% CI lower limit for seroprotection rates of HAI antibodies against each virus strain after 2nd vaccination≥70% | A seroprotected subject is defined as a vaccinated subject with serum HAI titer≥ 1:40. | day 28 after dose 2 | 
| Geometric Mean Fold Increase (GMFI) of HAI titer against each virus strain after 2nd vaccination>2.5 | Hemagglutination inhibition (HAI) titers were used to calculate post-vaccination geometric mean fold increase (GMFI) against each virus strain | day 28 after dose 2 | 
| Number of participants with Adverse Events (AEs) | Frequency and severity of AEs for 28 days after each vaccination | 28 days after each vaccination | 
| Number of participants with Serious Adverse Events (SAE) | Frequency of SAEs for 6 months after the last vaccination | 6 months after the last vaccination | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Safety, Immunogenicity, Quadrivalent influenza vaccine