A Study to Evaluate Immune Responses Following A/California/7/2009 (H1N1)V-like Virus Vaccination Given 4 Months Following Seasonal Influenza Vaccination in Adults 19 to 40 Years of Age

Inclusion Criteria:

- Subjects who the investigator believes can and will comply with the requirements of
the protocol (e.g., completion of the diary cards, return for follow-up visits).

- Written informed consent obtained from the subject.

- Male or female adults, 19-40 years of age at the time of the first vaccination.

- Body weight of at least 110 pounds (49.9 kg).

- Safety laboratory tests results within the parameters specified by protocol.

- Satisfactory baseline medical assessment by physical examination (stable health
status with no exclusionary conditions). Stable health status is defined as the
absence of a health event satisfying the definition of a serious adverse event, or a
change in an ongoing drug therapy due to therapeutic failure or symptoms of drug
toxicity, within one month prior to enrollment.

- Comprehension of the study requirements, ability to comprehend and comply with
procedures for collection of safety data, expressed availability for the required
study period, and ability and willingness to attend scheduled visits as documented by
signature on the informed consent document.

- 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 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 series

Exclusion Criteria:

- Previous vaccination with an A/California/7/2009 (H1N1)v-like virus vaccine

- A medical history of physician-confirmed infection with an A/California/7/2009
(H1N1)v-like virus.

- Prior receipt at any time of any seasonal influenza vaccine.

- Planned administration of any vaccine not foreseen by the study protocol (including
any influenza vaccine other than the study vaccine) between Days 0 and the Day 164
phlebotomy.

- Administration of any licensed vaccine within 30 days before the first study vaccine
dose.

- Use of any investigational or non-registered product (drug or vaccine) other than the
study vaccines within 30 days preceding the first dose of study vaccine, or planned
use during the study period.

- Receipt of systemic glucocorticoids (e.g., prednisone ≥ 0.5 mg/kg/day, or ≥ 10 mg/day
[whichever is less] for more than 14 consecutive days) within one month prior to
study enrolment, or any other cytotoxic or immunosuppressive drug within six months
of study enrolment. Topical, intra-articularly injected, or inhaled glucocorticoids,
topical calcineurin inhibitors or imiquimod are allowed.

- Receipt of any immunoglobulins and/or any blood products within 9 months of study
enrolment or planned administration of any of these products during the study period.

- Presence of evidence of substance abuse or of neurological or psychiatric diagnoses
which, even if stable, are deemed by the investigator to render the potential subject
unable/unlikely to provide accurate safety reports.

- History of anemia.

- Presence of a temperature ≥ 38.0ºC (≥100.4ºF), (oral temperature assessment
preferred), or acute symptoms greater than "mild" severity on the scheduled date of
first vaccination

- Diagnosed with cancer, or treatment for cancer, within 3 years.

- Any confirmed or suspected immunosuppressive or immunodeficient condition, based on
medical history and physical examination. (No laboratory testing is required.)

- 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 acetylsalicylic acid, and without a
clinically-apparent bleeding tendency, are eligible.

- An acute evolving neurological disorder or history of Guillain-Barré syndrome within
six weeks of receipt of any vaccine.

- Any known or suspected allergy to any constituent of influenza vaccines (including
egg proteins or mercurial preservatives); a history of anaphylactic-type reaction to
consumption of eggs; or a history of severe adverse reaction to any vaccine.

- Known pregnancy or a positive urine beta-human chorionic gonadotropin (β-HCG) test
result prior to first vaccination.

- Lactating or nursing women.