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 monthsthrough 8 years who have previously received ≥2 total doses of trivalent orquadrivalent influenza vaccine ≥4 weeks apart, they require only 1 dose ofinfluenza vaccine. For those who have not previously received ≥2 doses oftrivalent or quadrivalent influenza vaccine, they require 2 dose of influenzavaccine. but the evidence on how to select vaccine doses for quadrivalentinfluenza vaccine is limited in China. The study is a prospective, open-labelcomparison of the immunogenicity and reactogenicity of 1 versus 2 doses ofan inactivated quadrivalent influenza vaccine in subjects of 3-8 years old withdifferent 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 receiptof dose 1, 4 weeks after receipt of dose 1 and before dose 2, and 4 weeksafter dose 2. Hemagglutination inhibition (HAI) antibody titers to the A/H3N2,A/H1N1, and B antigens included in the vaccine were measured at each timepoint

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

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 theinformed consent Subjects themselves or their guardians can and will comply with therequirements of the protocol Subjects have received ≥2 doses of trivalent or quadrivalent infuenzavaccine before enrollment (Doses need not have been received duringsame or consecutive seasons); Subjects have not received infuenzavaccine before enrollment Subjects with temperature <=37.0°C on axillary setting Exclusion Criteria: Any prior administration of other research medicine/vaccine in last 30 days Any prior administration of influenza vaccine in last 6 month Any prior administration of immunodepressant or corticosteroids in last 3 months Any prior administration of blood products in last 3 months Any prior administration of any attenuated live vaccine in last 14 days Any prior administration of subunit or inactivated vaccines in last 7 days Subject who developed guillain-Barre syndrome post influenza vaccination Subject who is allergic to any ingredient of the vaccine Subject with acute febrile illness or infectious disease Thrombocytopenia, blood coagulation disorder or bleeding difficulties withintramuscular injection Subject with damaged or low immune function which has already beenknown Subject with congenital heart disease or other birth defects unsuitable for vaccination. Subject with respiratory diseases (including pneumonia, tuberculosis, severe asthma, etc.), heart, liver and kidney diseases, mental disorders, or chronic infections. Any medical, psychological, social or other condition judged byinvestigator, that may interfere subject's compliance with the protocol

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, and4 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 quadrivalentinfluenza vaccine, 4 weeks apart. Each 0.5-ml dosecontained 15 μg of hemagglutinin per strain. | Biological: Quadrivalent influenza vaccine<br>* Subjects receive two doses of quadrivalent influenzavaccine administered 4 weeks apart by intramuscularinjection. Each 0.5-ml dosecontained 15 μg of hemagglutinin per strain.<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 < 1:10and 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