Phase 2 Dose and Formulation Confirmation of Quad-NIV in Older Adults

Inclusion Criteria: 1. Clinically-stable adult male or female, ≥ 65 years of age. Subjects may have 1 or more chronic medical diagnoses, but should be clinically stable as assessed by: * Absence of changes in medical therapy within 1 month due to treatment failure or toxicity, * Absence of medical events qualifying as serious adverse events within 2 months; and * Absence of known, current, and life-limiting diagnoses which render survival to completion of the protocol unlikely in the opinion of the investigator. 2. Willing and able to give informed consent prior to trial enrollment, and 3. Living in the community and able to attend trial visits, comply with trial requirements, and provide timely, reliable, and complete reports of adverse events. Exclusion Criteria: 1. Participation in research involving investigational product (drug / biologic / device) within 45 days before planned date of first injection. 2. Participation in any previous Novavax's influenza vaccine clinical trial(s). 3. History of a serious reaction to prior influenza vaccination, known allergy to constituents of licensed comparator vaccines or polysorbate 80. 4. History of Guillain-Barré Syndrome (GBS) within 6 weeks following a previous influenza vaccine. 5. Received any vaccine in the 4 weeks preceding the trial vaccination and any influenza vaccine within 6 months preceding the trial vaccination. 6. Any known or suspected immunosuppressive illness, congenital or acquired, based on medical history and/or physical examination. 7. Chronic administration (defined as more than 14 continuous days) of immunosuppressants or other immune-modifying drugs within 6 months prior to the administration of the trial vaccine. An immunosuppressant dose of glucocorticoid will be defined as a systemic dose ≥ 10 mg of prednisone per day or equivalent. The use of topical, inhaled, and nasal glucocorticoids will be permitted. 8. Administration of immunoglobulins and/or any blood products within the 3 months preceding the administration of the trial vaccine or during the trial. 9. Acute disease at the time of enrollment (defined as the presence of a moderate or severe illness with or without fever, or an oral temperature ≥ 38.0°C, on the planned day of vaccine administration). 10. Any condition that in the opinion of the investigator would pose a health risk to the subject if enrolled or could interfere with evaluation of the vaccine or interpretation of trial results (including neurologic or psychiatric conditions deemed likely to impair the quality of safety reporting). 11. Known disturbance of coagulation. 12. Suspicion or recent history (within 1 year of planned vaccination) of alcohol or other substance abuse.