Safety and Immunogenicity of a Paediatric Dose of Virosomal Hepatitis A Vaccine

Study Overview
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Brief Summary
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The primary purpose of the original study was to assess whether the protection afforded by the paediatric dose of Epaxal vaccine against hepatitis A was not inferior to the protection afforded by the standard dose of Epaxal. The aim of the follow-up phase was to perform a computer based modelling analysis of the long term protection afforded by the paediatric dose, and to compare this with the standard dose and also with an alternative hepatitis A vaccine (Havrix Junior).

Official Title
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A Phase II Open, Randomised, Controlled Study to Evaluate the Safety and Immunogenicity of a Paediatric Dose (0.25 mL) and the Standard Dose (0.5 mL) of Epaxal® With Reference to Havrix Junior® Healthy in Healthy Children and Adolescents (>=12 Months - 16 Years of Age) Using a 0/6 Month Schedule

Conditions
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Hepatitis A

Intervention / Treatment
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* Biological: Epaxal 0.25 mL
* Biological: Epaxal 0.5 mL
* Biological: Havrix Junior 0.5 mL


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Original study: Males or females aged >=12 months and 16 years of age at the time of the first vaccination. Written informed consent obtained from the subject when applicable and from the parent/legal guardian of the subject. - Free of obvious health problems as established by medical history and/or clinical examination before entering the study. Follow up phase: Subjects enrolled and randomized in the primary study and having received two doses of the study vaccine Exclusion Criteria: Use of any investigational or non-registered drug or vaccine within 30 days preceding the first dose of study vaccine, or planned use during the study period and safety follow-up Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose. (For corticosteroids, this means prednisone, or equivalent, >=0.5 mg/kg/day. Inhaled and topical steroids were allowed.) Planned administration/administration of a vaccine not foreseen by the study protocol within 4 weeks prior to the first dose of study vaccine Previous vaccination against hepatitis A Seropositive for anti-HAV antibodies (>=10 mIU/mL) Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection History of allergic disease or reactions likely to be exacerbated by any component of the vaccine. Major congenital defects or serious chronic illness Acute disease at the time of enrolment

Ages Eligible for Study
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Minimum Age: 12 Months
Maximum Age: 16 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Epaxal 0.25 mL<br>Single intramuscular dose (M. deltoideus) given on Day 1 and at Month 6 | Biological: Epaxal 0.25 mL<br>* 12 IU hepatitis A antigen coupled to immunopotentiating reconstituted Influenza virosome (IRIV)<br>|
| Active Comparator: Epaxal 0.5 mL<br>Single intramuscular dose (M. deltoideus) given on Day 1 and at Month 6 | Biological: Epaxal 0.5 mL<br>* 24 IU hepatitis A antigen coupled to IRIV<br>|
| Active Comparator: Havrix Junior<br>Single intramuscular dose (M. deltoideus) given on Day 1 and at Month 6 | Biological: Havrix Junior 0.5 mL<br>* 720 EU hepatitis A antigen absorbed onto aluminum hydroxide<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Individual anti-HAV titers | Real-time seroprotection analysis and computer modelling will be conducted up to 5 years post-booster to estimate long term seroprotection | 66 months post-booster | 
| Individual anti-HAV titers | Real-time seroprotection analysis and computer modelling will be conducted up to 5 years post-booster to estimate long term seroprotection | 18 months post-booster | 
| Individual anti-HAV titers | Real-time seroprotection analysis and computer modelling will be conducted up to 5 years post-booster to estimate long term seroprotection | 30 months post-booster | 
| Individual anti-HAV titers | Real-time seroprotection analysis and computer modelling will be conducted up to 5 years post-booster to estimate long term seroprotection | 42 months post-booster | 
| Individual anti-HAV titers | Real-time seroprotection analysis and computer modelling will be conducted up to 5 years post-booster to estimate long term seroprotection | 54 months post-booster | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Geometric mean titers |  | 18, 30, 42, 54, 66 months post-booster | 
| Seroprotection | Porportion of subjects who are seroprotected calculated at each time point where seroprotection is defined as >=10 mIU/mL | 18, 30, 42, 54, 66 months post-booster | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hepatitis A, Vaccination, Immunisation