Immunogenicity and Safety Study of GlaxoSmithKline (GSK) Biologicals' Fluviral® (2012/2013 Season) in Adults

Inclusion Criteria: * Subjects who, in the opinion of the investigator, can and will comply with the requirements of the protocol. * A male or female 18 years of age and older at the time of the first vaccination. * Written informed consent obtained from the subject. * Healthy subjects as established by medical history and clinical examination before entering into the study. * Female subjects of non-childbearing potential may be enrolled in the study. * Female subjects of childbearing potential may be enrolled in the study, if the subject: * has practiced adequate contraception for 30 days prior to vaccination, and * has a negative pregnancy test on the day of vaccination, and * has agreed to continue adequate contraception during the entire treatment period and for 2 months after completion of the vaccination. Exclusion Criteria: * Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine within 30 days preceding the dose of study vaccine, or planned use during the study period. * Administration of any influenza vaccine within 6 months preceding the study start or planned use of such vaccines during the study period. * Administration of any other vaccine(s) within 30 days prior to study enrolment or during the study period. * Clinically or virologically confirmed influenza infection within the six months preceding the study vaccination. * Acute disease and/or fever at the time of enrolment. * Significant acute or chronic, uncontrolled medical or psychiatric or neurological illness. * Any confirmed or suspected immunosuppressive or immunodeficient condition. * Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests. * Insulin-dependent diabetes mellitus. * Presence of blood dyscrasias, including hemoglobinopathies and myelo- or lymphoproliferative disorder. * Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the vaccine dose. * A history of any demyelinating disease including Multiple Sclerosis and Guillain-Barré syndrome. * History of chronic alcohol abuse and/or drug abuse as deemed by the investigator to render the potential subject unable/unlikely to provide accurate safety reports. * Any significant disorder of coagulation that increases the risk of intramuscular injections or treatment with coumadin derivatives or heparin. Persons receiving prophylactic antiplatelet medications, e.g. low-dose aspirin, and without a clinically-apparent bleeding tendency are eligible. * Administration of immunoglobulins and/or any blood products within the three months preceding the administration of the study vaccine or planned during the study. * Any known or suspected allergy to any constituent of Fluviral® and/or a history of anaphylactic type reaction to consumption of eggs, and/or reactions to products containing mercury. * A history of severe adverse reaction to a previous influenza vaccination. * Pregnant and/or lactating/nursing female. * Any condition which, in the opinion of the investigator, prevents the subject from participation in the study.