Inclusion Criteria:

Subjects must meet all of the following inclusion criteria to be eligible for study participation:

• Ambulatory medically stable persons >= 65 years of age on the date of vaccination
• Provides written informed consent and will be available for all study visits
• Able to understand and comply with planned study procedures

Subjects will be considered ambulatory if they are not institutionalized, bedridden, or homebound. Medically stable subjects may have underlying illnesses such as hypertension, diabetes, ischemic heart disease, or hypothyroidism, but their symptoms/signs must be controlled with medical therapy. Subjects with acute febrile illnesses [oral temperature equal to or exceeding 99.5ºF (37.5ºC)] will be deferred until 3 days after illness resolution.

Exclusion Criteria:

Subjects must not meet any of the following exclusion criteria in order to be eligible for participation in this study:

• Known allergy to eggs or other components of the vaccine (eg, thimerosal);
• History of a severe reaction following influenza vaccination, systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to a vaccine containing the same substances;
• History of Guillain-Barré Syndrome;
• Immunosuppression as a result of underlying illness or treatment;
• Use of oral steroids, parenteral steroids, or high-dose inhaled steroids (> 800 µg per day of beclomethasone dipropionate or equivalent) within 1 month prior to vaccination;
• Use of other immunosuppressive or cytotoxic drugs or radiation therapy within the six months prior to vaccination;
• Active neoplastic disease or history of any hematologic malignancy in the past 5 years (except localized skin or prostate cancer that is stable in the absence of therapy);
• Acute or chronic condition that (in the opinion of the Investigator) would render vaccination unsafe or would interfere with the evaluation of responses including, but not limited to the following: known chronic liver disease, significant renal disease, oxygen-dependent chronic lung disease, New York Heart Association Functional Class III or IV, unstable or progressive neurologic disorder, insulin-treated diabetes mellitus;
• Use of experimental vaccines or medications within the month prior to study entry, or expected use of experimental vaccines or medications during the entire study period, including the 6-month follow-up phone call, after inoculation with study vaccine;
• Use of experimental devices or participation in a medical procedure trial within the month prior to study entry, or expected use of experimental devices or participation in a medical procedure trial during the entire study period, including the 6-month follow-up phone call, after inoculation with study vaccine;
• Receipt of immunoglobulin or other blood product within 3 months prior to enrollment;
• Receipt of other licensed vaccines within the preceding 4 weeks or expected to receive a licensed vaccine within 1 month (prior to visit 2) following trial vaccination;
• Subject is enrolled in a conflicting clinical trial;
• Thrombocytopenia or bleeding disorder or therapy contraindicating IM vaccination.