Inclusion Criteria: 

• Must be able to provide signed and dated informed consent.
• Is 18 to 30, 65 to 75, or ≥ 75 years old at time of consent.
• Determined by medical history, physical examination, and clinical judgment to be generally healthy, with no immunosuppressive conditions and having stable current medical conditions. Subjects with preexisting, stable disease, defined as not requiring significant change in therapy or hospitalization for worsening of disease 12 weeks prior to receipt of study vaccine are eligible. A change in dose or therapy within a treatment category (e.g., change from one non-steroidal anti-inflammatory drug to another) is allowed. A change to a new therapy category (e.g., surgery or addition of a new pharmacological class) is only allowed if it is not caused by worsening disease.
• Is eligible for the 2014-2015 seasonal influenza vaccine.
• Is available for Visits 2 and 3 on Days 1 and 28 (±2 days).
• Is willing to follow study procedures.
• Able to follow study procedures in the opinion of the investigator.

Exclusion Criteria: 

• A change to a new therapy category caused by worsening disease is considered significant and will disqualify subject from participating in the study.
• Subjects reporting any symptoms suggestive of influenza, influenza-like illness, or respiratory illness.
• Vaccination during the 2014-2015 influenza season(after May of the 2014 calendar year) with any licensed or experimental influenza vaccine.
• History of severe adverse reaction associated with an influenza vaccine.
• Allergic to egg proteins (egg or egg products) and chicken proteins.
• History of Guillain-Barré syndrome.
• Known or suspected immunodeficiency or receiving treatment with immunosuppressive therapy including cytotoxic agents or systemic corticosteroids (e.g., transplant recipients on active immunosuppression, patients with cancer, HIV, or autoimmune disease). If systemic corticosteroids have been administered short term for treatment of an acute illness, subjects will be excluded from the study until corticosteroid therapy had been discontinued for at least 30 days.
• Serious chronic medical condition including: metastatic malignancy, severe chronic obstructive pulmonary disease requiring supplemental oxygen, end stage renal disease with or without dialysis, clinically unstable cardiac disease, or any other disorder that in the investigator’s opinion should preclude the subject from participating in the study.
• Receipt of any blood products, including immunoglobulin, within six months of study enrollment.
• Donated blood within last 58 days.
• Current anticoagulant therapy or a history of bleeding diathesis that would contraindicate intramuscular (IM) injection (Note: antiplatelet drugs such as aspirin and clopidogrel are permitted)
• Intent to receive any other investigational vaccine or agent during the course of the study.
• Any medical condition that would, in the opinion of the investigator, interfere with the evaluation of the study objectives.
• Pregnant women. Our study is evaluating the impact of age on vaccine-induced inflammasome activation and adaptive influenza-specific immunity. Pregnancy is associated with immunological variations that could impact vaccine response, and would confound the results of our study. 

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 10/15/2024. Questions regarding updates should be directed to the study team contact.