Clinical Study to Evaluate the Efficacy, Safety and Immunogenicity of QIVc in Subjects ≥2 to <18 Years of Age

This Phase 3/4, randomized, observer-blind, multi-center study, stratified study evaluated the immune (antibody) response, efficacy and safety of a cell-derived quadrivalent subunit influenza virus vaccine (Seqirus QIVc) in comparison with a non-influenza comparator, meningococcal serogroup A, C, W-135, and Y (Menveo®, GlaxoSmithKline Biologicals, S.A.) in healthy pediatric subjects ≥2 Years to \<18 Years of Age

This Phase 3/4, randomized, observer-blind, multi-center, stratified study evaluated the efficacy, safety, and immunogenicity of a cell-derived quadrivalent subunit influenza virus vaccine (Seqirus QIVc) compared to a non-influenza comparator vaccine in healthy male and female participants between 2 to \<18 years of age. A total of 4514 children/teens were randomized, receiving either QIVc or the non-influenza comparator vaccine. The comparator was (meningococcal \[Groups A, C, W-135, and Y\] oligosaccharide diphtheria CRM197 conjugate vaccine \[Men ACWY\]). Randomized enrollment was stratified in a 1:1 ratio via an Interactive Response Technology (IRT) system which assigned the participants into two age cohorts: 2 to \<9 years of age and 9 to \<18 years of age. Subjects between 2 to \<9 years of age were further stratified by previous influenza vaccine status ("previously vaccinated" or "not previously vaccinated").

Eligibility Criteria:
Inclusion Criteria:

* Male or female ≥2 to \<18 years of age on the day of the first study vaccination
* Subject's parent(s) or legal guardian(s) who was/were able to give informed consent/dissent after the nature of the study had been explained in accordance with the practices described in the study and according to local regulatory requirements
* If the subject was of an age where, according to local regulations, informed assent was required, he/she must have provided assent to participate in the study
* Subject/subject's parent(s) or legal guardian(s) was/were able to comply with study procedures and was/were available for follow-up; and
* Subject was in generally good health as per the investigator's medical judgment

Exclusion Criteria:

* Clinical signs of fever and/or an oral temperature of ≥100.4°F (38.0°C) within 3 days prior to vaccination;
* A known history of any anaphylaxis, serious vaccine reactions or hypersensitivity to any of the vaccine components described in the Investigator's Brochure, or had any of the contraindications listed in the package insert of the comparator vaccine;
* A history of Guillain-Barré syndrome or other de-myelinating diseases such as encephalomyelitis and transverse myelitis;
* Female subject of childbearing potential (ie, post onset of menarche and before natural or induced menopause), sexually active, and who did not use any acceptable contraceptive methods for at least 2 months prior to study entry and who did not intend to use any acceptable contraceptive methods throughout subject participation (acceptable contraceptive methods included: abstinence; hormonal contraceptive \[such as oral, injection, transdermal patch, implant\]; diaphragm with spermicide; tubal occlusion device; intrauterine device \[IUD\]; tubal ligation; male partner using condom; or male partner having been vasectomized);
* Pregnant or breast feeding female;
* Subject and/or subject's parent/guardians who were not able to comprehend or follow all required study procedures for the entire period of the study;
* Received prior Meningococcal ACWY vaccination that conflicted with national recommendations or local practices for the timing of the primary or the booster vaccination;
* Received influenza vaccination or had documented influenza disease in the last 6 months;
* Known or suspected congenital or acquired immunodeficiency; or received immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or systemic corticosteroid therapy (prednisone or equivalent) at any dose for more than 2 consecutive weeks (14 days) within the past 3 months. Topical, inhaled and intra-nasal corticosteroids were permitted. Intermittent use (1 dose in 30 days) of intra-articular corticosteroids was also permitted;
* Administration of immunoglobulin and/or any blood products within the 3 months preceding vaccination, or administration was planned during the study;
* Participated in any clinical study with another investigational product within 30 days prior to first study visit or intended to participate in another clinical study at any time during the conduct of this study. Concomitant participation in an observational study (not involving drugs, vaccines, or medical devices) was acceptable;
* Medical conditions or treatments contraindicating IM vaccination due to increased risk of bleeding. These included known bleeding disorders (such as thrombocytopenia), or treatment with anticoagulants (such as warfarin) in the 3 weeks preceding vaccination. Antiplatelet agents such as low-dose aspirin, ticlopidine (Ticlid) and clopidogrel (Plavix) were permitted;
* Evidence or history (within the previous 12 months) of drug or alcohol abuse;
* Study personnel or immediate family members (brother, sister, child, parent), the spouse of study personnel or individuals who were financially or emotionally dependent on study staff;
* Participated in this study in a prior season, if applicable; or
* Any clinical condition that, in the opinion of the investigator, may have interfered with the results of the study or pose additional risk to the subject due to participation in the study.