Study to Evaluate the Safety and Immunogenicity of GlaxoSmithKline (GSK) Biologicals' Influenza Vaccines GSK2654911A and GSK2654909A Administered to Adults 18 to 64 Years of Age

Inclusion Criteria: * Male or female adults from 18 to 64 years of age (inclusive) at time of first study vaccination. * Written informed consent obtained from the subject. * Subjects who the investigator believes can and will comply with the requirements of the protocol. * Healthy subjects as established by medical history and physical examination. * Body weight of at least 110 lbs (49.9 kg). * Access to a consistent means of telephone contact, which may be either in the home or at the workplace, land line or mobile, but NOT a pay phone or other multiple-user device (i.e., a common-use phone serving multiple rooms or apartments). * Female subjects of non-childbearing potential may be enrolled in the study. Non-childbearing potential is defined as current tubal ligation, hysterectomy, ovariectomy or post-menopause. * Female subjects of childbearing potential may be enrolled in the study, if they have practiced adequate contraception for 30 days prior to vaccination, and have a negative pregnancy test on the day of vaccination, and agree to continue to practice adequate contraception until 2 months after booster dose administration. Exclusion Criteria: * Presence or evidence of neurological or psychiatric diagnoses which, although stable, are deemed by the investigator to render the potential subject unable/unlikely to provide accurate safety reports. * Presence or evidence of substance abuse. * Diagnosed with cancer, or treatment for cancer within three years. * Persons with a history of cancer who are disease-free without treatment for three years or more are eligible. * Persons with a history of histologically-confirmed basal cell carcinoma of the skin successfully treated with local excision only are excepted and may enroll, but other histologic types of skin cancer are exclusionary. * Women who are disease-free three years or more after treatment for breast cancer and receiving long-term prophylaxis may enroll. * Presence of a temperature ≥ 38.0ºC (≥100.4ºF), or acute symptoms greater than "mild" severity on the scheduled date of first vaccination. * Any confirmed or suspected immunosuppressive or immunodeficient condition including history of human immunodeficiency virus (HIV) infection (no laboratory testing required). * Receipt of systemic glucocorticoids (e.g., prednisone ≥ 10 mg/day for more than 14 consecutive days) within 30 days prior to the first dose of study vaccine, or any other cytotoxic, immunosuppressive or immune-modifying drugs within 365 days of study enrollment. Topical, intra-articularly injected, or inhaled glucocorticoids, topical calcineurin inhibitors or imiquimod are allowed. * Any significant disorder of coagulation or treatment with warfarin derivatives or heparin. Persons receiving individual doses of low molecular weight heparin outside of 24 hours prior to vaccination are eligible. Persons receiving prophylactic antiplatelet medications, e.g., low-dose aspirin, and without a clinically-apparent bleeding tendency, are eligible. * An acute evolving neurological disorder or Guillain Barré Syndrome within 42 days of receipt of prior seasonal or pandemic influenza vaccine. * Administration of an inactive vaccine within 14 days or of a live attenuated vaccine within 30 days before the first dose of study vaccine/product. * Planned administration of any vaccine other than the study vaccine/product before blood sampling at the Day 42 visit. * Previous administration of any H9 vaccine or physician-confirmed H9 disease. * Use of any investigational or non-registered product other than the study vaccine within 30 days preceding the first dose of study vaccine, or planned use during the study period. * Receipt of any immunoglobulins and/or any blood products within 90 days before study enrolment or planned administration of any of these products during the study period. * Any known or suspected allergy to any constituent of influenza vaccines or component used in the manufacturing process of the study vaccine including a history of anaphylactic-type reaction to consumption of eggs; or a history of severe adverse reaction to a previous influenza vaccine. * Known pregnancy or a positive urine beta-human chorionic gonadotropin (β-hCG) test result before the first vaccination. * Lactating or nursing women. * Any condition which, in the opinion of the investigator, prevents the subject from participating in the study.