A Study to Evaluate the Immunogenicity and Safety of Seqirus Quadrivalent Influenza Vaccine (QIV) in a Pediatric Population 5 Through 17 Years of Age

Inclusion Criteria: * Males or females 5 through 17 years of age on the day of first study vaccination. * Parent or legally acceptable representative able to provide written informed consent and be willing and able to adhere to all protocol requirements including blood draws. Participant assent will also be obtained if required. * If applicable, females of childbearing potential (ie, ovulating, not surgically sterile) must be abstinent or be willing to use a medically accepted contraceptive regimen until at least 28 days after the last Study Vaccine. Females of childbearing potential must return a negative urine pregnancy test result, prior to any vaccination dose with the Study Vaccine. Exclusion Criteria: * History of allergic reactions to egg proteins or any components of the Study Vaccines. * History of serious adverse reactions to any influenza vaccines. * History of Guillain-Barré syndrome or other demyelinating disease. * History of licensed or investigational influenza vaccination in the last 6 months. * Clinical signs of active infection and/or an oral temperature of ≥ 100°F (37.8°C) on the day of planned Study Vaccine administration or within 48 hours preceding vaccination. * Current or recent, acute or chronic medical conditions that in the opinion of the Investigator are clinically significant and/or unstable (such as illness exacerbations) within the preceding 30 days. * History of any seizures, with the exception of a single febrile seizure. * Self-reported or known seropositivity suggestive of acute or chronic viral infection for human immunodeficiency virus, hepatitis B or hepatitis C. * Known or suspected congenital or acquired immunosuppressive conditions. * Current or recent immunosuppressive or immunomodulatory therapy, as follows: * Chronic or long-term systemic corticosteroids: ≥ 0.125 mg/kg/day of oral prednisolone or equivalent daily; * Sporadic systemic corticosteroids: ≥ 0.5 mg/kg/day of oral prednisolone or equivalent for two or more short courses of \> 3 days in the 3 months preceding vaccination; * Antineoplastic chemotherapy or radiation therapy within the 6 months preceding vaccination. Note: Use of topical, inhalant or localised tissue injections of corticosteroids prior to administration of the Study Vaccine or throughout the study are acceptable. * Administration of immunoglobulin and/or any blood products within the 3 months preceding vaccination, or planned administration during the study. * Participation in a clinical trial or use of an investigational compound within 28 days prior to the first dose of Study Vaccine, or within 28 days after receiving the final indicated dose of Study Vaccine, or plans to enter a study during this period. * Vaccination with a licensed vaccine 28 days (for live or inactivated vaccines) prior to receiving the first dose of Study Vaccine, or plans to receive any licensed vaccine prior to the Study Exit Visit. * Pregnant or lactating females.