Safety and Immunogenicity of 2 Formulations of an Intramuscular A/H5N1 Pandemic Influenza Vaccine in Children

This is an open, randomized, multicenter clinical trial.

Objectives:

* To describe the safety profiles during the 21 days following each primary and booster injection.
* To describe the immune response 21 days after each primary and booster injection of each formulation.
* To describe the antibody persistence after the first vaccination


Eligibility Criteria:
Inclusion Criteria :

All subjects:

* Able to attend all scheduled visits and to comply with all trial procedures.

Children/Adolescents aged ≥ 2 years to \< 18 years:

* Aged ≥ 2 years to \< 18 years on the day of inclusion.
* Informed Consent Form signed by one parent or another legal representative and by an independent witness if the parent/legal representative is illiterate.
* For a female, inability to bear a child or negative urine pregnancy test (as applicable).
* For a female of child-bearing potential, use of an effective method of contraception or abstinence for at least 4 weeks prior to the first vaccination and at least 4 weeks after the last vaccination (as applicable).

Infants/toddlers aged ≥ 6 months to \< 2 years:

* Aged ≥ 6 months to \< 2 years on the day of inclusion.
* Born at full term of pregnancy (≥ 37 weeks) with a birth weight ≥ 2 kg.
* Informed Consent Form signed by one parent/legally acceptable representative and an independent witness if the parent/legally acceptable representative is illiterate.
* Subject who completed vaccination according to the national immunization schedule.

Exclusion Criteria :

All subjects:

* Participation in another clinical trial in the 4 weeks preceding the first trial vaccination.
* Planned participation in another clinical trial during the present trial period.
* Congenital or acquired immunodeficiency, immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months, or long-term systemic corticosteroid therapy.
* Systemic hypersensitivity to any of the vaccine components or history of life threatening reaction to the trial vaccine or a vaccine containing the same substances (egg proteins, chick proteins, thimerosal, aluminum, neomycin, formaldehyde, and octoxinol 9).
* Chronic illness at a stage that could interfere with trial conduct or completion.
* Blood or blood-derived products received in the past 3 months.
* Any vaccination in the 4 weeks preceding the first trial vaccination.
* Vaccination planned in the 4 weeks following any trial vaccination.
* History of the H5N1 infection (confirmed either clinically, serologically or virologically).
* Known HIV, Hepatitis B (HBsAg) or Hepatitis C seropositivity.
* Previous vaccination with an avian flu vaccine.
* Subject at high risk of the H5N1 infection during the trial.
* Thrombocytopenia or bleeding disorder contraindicating IM vaccination.
* Febrile illness (rectal equivalent temperature ≥ 38.0°C) on the day of inclusion.

Children/Adolescents aged ≥ 2 years to \< 18 years:

* Breast-feeding mothers.
* Current alcohol abuse or drug addiction that may interfere with the subject's ability to comply with trial procedures (if applicable, depending on the subject's age).

Infants/toddlers aged ≥ 6 months to \< 2 years:

* History of seizures.