Immunogenicity and Safety Study of an Investigational Influenza (H1N1 Influenza Virus) Vaccine in Adults

The objective of this study is to evaluate the immunogenicity and safety of GSK Biologicals' investigational vaccine GSK2340272A in adults aged 18 to 60 years.

This Protocol Posting has been updated following Protocol amendment 1, October 2009. The impacted section is the outcomes measures section.

Eligibility Criteria:
Inclusion Criteria:

* A male or female aged 18 to 60 years at the time of the first vaccination.
* Subjects who the investigator believes that they can and will comply with the requirements of the protocol.
* Written informed consent obtained from the subject.
* Satisfactory baseline medical assessment by history and physical examination. Stable health status is defined as the absence of health event satisfying the definition of an SAE, or a change in an ongoing drug therapy due to therapeutic failure or symptoms of drug toxicity, within one month prior to enrolment.
* 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 multiple-user device.
* 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 two months after completion of the vaccination series.

Exclusion Criteria:

* Use of any investigational or non-registered product other than the study vaccine within 30 days preceding the first dose of the study vaccine or planned use during the study period. Potential subjects in the follow-up phase of a prior investigational study may be enrolled if the investigator's judgment is that it will have no effect on safety, reactogenicity, or immunogenicity endpoints in this study, and that it does not violate the protocol requirements of the prior trial.
* Presence of evidence of substance abuse or 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 of an axillary temperature \>= 37.5°C, or acute symptoms greater than "mild" severity on the scheduled date of first vaccination.
* Diagnosed with cancer, or treatment for cancer, within the past three years.
* Any confirmed or suspected immunosuppressive or immunodeficient condition including history of human immunodeficiency virus (HIV) infection.
* Clinically or virologically confirmed influenza infection within six months preceding the study start.
* Chronic administration of immunosuppressants or other immune modifying drugs within six months of study enrolment or planned administration during the study period. For corticosteroids, this will mean a dose equivalent to 20 mg/day of prednisone or equivalent for persons for \> two weeks. Inhaled and topical steroids are allowed.
* Receipt of any immunoglobulins and/or any blood products within three months of study enrolment or planned administration of any of these products during the study period.
* 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 and without a clinically-apparent bleeding tendency, are eligible.
* An acute evolving neurological disorder or history of Guillain-Barré syndrome.
* Administration of any vaccines within 30 days before vaccination.
* Any known or suspected allergy to any constituent of influenza vaccines; a history of anaphylactic-type reaction to any constituent of influenza vaccines; or a history of severe adverse reaction to a previous influenza vaccine.
* Pregnant or lactating female.
* Female planning to become pregnant or planning to discontinue contraceptive precautions.
* Any conditions which, in the opinion of the investigator, prevents the subjects from participating in the study.