Safety and Immune Response Study of GSK Biologicals' Influenza Virus Vaccine 1388442A Compared With Fluarix

Inclusion Criteria: * Subjects who the investigator believes can and will comply with the requirements of the protocol * A male or non-pregnant, non-lactating female between 18 and 49 years of age at the time of vaccination * Access to a telephone for scheduled follow-up telephone contacts * Ability to provide written informed consent * Healthy subjects as established by medical history and physical examination before entering into the study * If the subject is female, she must be of non-childbearing potential, or if she is of childbearing potential, she must practice adequate contraception for 30 days prior to vaccination and continue such precautions for 2 months after receipt of the study vaccine. All women will have a pregnancy test on the day of 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 * Receipt of systemic glucocorticoids within 30 days of study enrollment * Administration of immunosuppressant, cytotoxic, or other immune-modifying drugs (other than glucocorticoids) or irradiation within 6 months prior to study enrollment or planned administration during the study period * Administration of immunoglobulins and/or blood products within 3 months prior to study enrollment or planned administration during the study period * Previous vaccination against influenza (2007-2008 influenza season) * History of anaphylactic or other allergic reaction to influenza vaccine, any other vaccine, or any vaccine component or excipient * History of Guillain-Barre Syndrome (GBS) * Acute disease, febrile illness, or upper respiratory infection at screening. * History of splenectomy * Any confirmed or suspected, acquired, congenital, or hereditary immunodeficiency or immunosuppressive condition (including human immunodeficiency virus \[HIV\]) based on medical history and physical examination * Acquired or congenital coagulation disorders or known thrombocytopenia * Current treatment with warfarin or heparin derivatives * Known use of an analgesic or antipyretic medication within 12 hours prior to treatment for the purposes of prophylaxis of adverse events * Any medical condition for which the US Advisory Committee on Immunization Practices recommends vaccination against influenza