Study With Quadrivalent Recombinant Influenza Vaccine (RIV4) Compared With Egg-Based Quadrivalent Influenza Vaccine (IIV4) in Participants Aged 3 to 8 Years

Study Overview
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Brief Summary
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The purpose of this study is to demonstrate the non-inferior HAI immune response of quadrivalent recombinant influenza vaccine (RIV4) vs licensed Egg-Based Quadrivalent Influenza Vaccine (IIV4) for the 4 strains based on the egg-derived antigen in all participants aged 3 to 8 years and to describe the immunogenicity and safety profile of RIV4 compared to IIV4 in participants aged 3 to 8 years.

Detailed Description
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Participants will be enrolled on the day of their first vaccination to receive 1 or 2 doses 28 days apart of either RIV4 or IIV4; depending on if they were previously vaccinated against influenza or previously unvaccinated against influenza, respectively; and will be followed for 6 months after the last vaccination.

Official Title
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Immunogenicity and Safety of Quadrivalent Recombinant Influenza Vaccine Compared With Egg-Based Standard-Dose Quadrivalent Influenza Vaccine in Children 3 to 8 Years of Age.

Conditions
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Influenza Immunization

Intervention / Treatment
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* Biological: Recombinant influenza vaccine (RIV4)
* Biological: Quadrivalent influenza vaccine (IIV4)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 3 to 8 years on the day of inclusion Assent form has been signed and dated by the participant (according to local regulations), and informed consent form has been signed and dated by the parent(s) or another legally acceptable representative and by an independent witness, if required by local regulations Exclusion Criteria: Known or suspected congenital or acquired immunodeficiency, or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccines used in the trial or to a vaccine containing any of the same substances Thrombocytopenia Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular vaccination based on the Investigator's judgment Personal or family history of Guillain-Barre Syndrome (GBS) Personal history of clinically significant development delay (at the discretion of the Investigator), neurologic disorder, or seizure disorder NOTE: The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial

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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: RIV4 cohort<br>RIV4 single injection at Day 1 | Biological: Recombinant influenza vaccine (RIV4)<br>* Pharmaceutical form: solution for injection Route of administration: intramuscular<br>* Other names: Supemtek / Flublok Quadrivalent;|
| Active Comparator: IIV4 cohort<br>IIV4, single injection at Day 1 | Biological: Quadrivalent influenza vaccine (IIV4)<br>* Pharmaceutical form: suspension for injection Route of administration: intramuscular<br>* Other names: Fluarix Tetra / Fluarix® Quadrivalent;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Individual Hemagglutination inhibition (HAI) titer at D29 after last vaccination | Antibody titers are expressed as GMTs | Day 29 or Day 57 | 
| Percentage of participants achieving seroconversion | Seroconversion for participants with a pre-vaccination titer lower than (<) 10 [1/dil] at D01 and a post-vaccination titer ≥ 40 [1/dil] at D29 or D57, or a pre-vaccination titer ≥ 10 [1/dil] at D1 and a ≥ 4-fold increase in post-vaccination titer at D29 or D57 | Day 29 or Day 57 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Individual Hemagglutination inhibition (HAI) titer at Day01 and at D29 after vaccination |  | Day 1 and Day 29 or Day 57 | 
| Percentage of participants with detectable antibody titers greater than or equal to (≥) 10 [1/dil] |  | Day 1 and Day 29 or Day 57 | 
| Percentage of participants with antibody titers greater than or equal to (≥) 40 [1/dil] |  | Day 1 and Day 29 or Day 57 | 
| Occurrence of immediate adverse events (AEs) | Immediate adverse events include unsolicited systemic adverse events within 30 minutes after vaccination | Within 30 minutes after each vaccination | 
| Occurrence of solicited injection site reactions and systemic reactions | Adverse reactions pre-listed in the (electronic) case report book (CRB) Injection site reactions: pain, redness, swelling, hardening, bruising Systemic reactions: fever, headache, malaise, myalgia | Within 8 days after each vaccination | 
| Occurrence of unsolicited AEs | AEs that other than solicited reactions | Up to 28 days after each vaccination | 
| Occurrence of attended adverse event (MAAEs) |  | Up to 28 days after each vaccination | 
| Occurrence of serious adverse events (SAEs) | SAEs, including adverse event of special interest (AESIs) | From Day 1 until the EoS (up to 6 months after vaccination) |