The aim of the study is to describe the immunogenicity and safety of the new formulation of Quadrivalent Influenza Vaccine (QIV) for the 2013-2014 season in the Northern Hemisphere (NH) in subjects aged 9 to 17 years in Taiwan

Primary Objective:

• To describe the immunogenicity of the QIV (split-virion, inactivated) NH seasonal formulation

Secondary Objective:

• To describe the safety of the QIV (split-virion, inactivated) NH seasonal formulation

Study participants will be vaccinated with one dose of the QIV (split-virion, inactivated) NH 2013-2014 formulation by the intramuscular route or deep subcutaneous. Immunogenicity will be assessed at baseline (Day 0) and 21 days after injection; they will also be followed-up for safety for 21 days after injection.

Inclusion Criteria:

• Aged 9 to 17 years on the day of inclusion
• Assent form (AF) and/or informed consent form (ICF) have been signed and dated by the subject according to each site requirements, and ICF has been signed and dated by the parent(s) or another legally acceptable representative(s) and by an independent witness if applicable
• Subject and parent/legally acceptable representative are able to attend all scheduled visits and to comply with all trial procedures.

Exclusion Criteria:

• Subject is pregnant (or positive urine pregnancy test), or lactating, or of childbearing potential (to be considered of non-childbearing potential, a female must be post-menopausal for at least 1 year, surgically sterile, or using an effective method of contraception or abstinence from at least 4 weeks prior to vaccination and until at least 4 weeks after vaccination)
• Participation at the time of study enrollment or in the 4 weeks preceding the trial vaccination or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure
• Receipt of any vaccine in the 4 weeks preceding the trial vaccination or planned receipt of any vaccine in the 3 weeks following trial vaccination
• Vaccination against influenza in the previous 12 months if administered in the context of a clinical trial or in the previous 6 months if administered in the context of a flu vaccination campaign
• Receipt of immune globulins, blood or blood-derived products in the past 3 months
• 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)
• Self-reported history of seropositivity for Human Immunodeficiency Virus (HIV), Hepatitis B, or Hepatitis C, after questioning
• Known systemic hypersensitivity to eggs, chicken proteins, neomycin, formaldehyde and octoxynol-9, or to any of the vaccine components, or history of a life-threatening reaction to the vaccine used in the study or to a vaccine containing any of the same substances
• Known or suspected thrombocytopenia, contraindicating intramuscular vaccination based on investigator's judgment
• Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular vaccination upon investigator's judgment
• Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily
• Current alcohol abuse or drug addiction
• Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion
• Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature ≥38.0°C). A prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided
• Identified as a family member (i.e., parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study.

Adverse event data were collected from Day 0 (post vaccination) up to Day 7 post vaccination.