Patient description: A 42-year-old healthy woman came to the clinic to have her flu shot in early October. She works in a rehab center and has no underlying disease. It's her first time getting the vaccine this year. She is married for 5 years and uses barrier methods of contraception. Her menstrual cycle is irregular. She does not smoke. She is not on any medications. She exercises regularly for 30 minutes a day at least 5 days a week. She has no history of allergies to any food or drugs. Her past surgical history is significant for tonsillectomy and she is otherwise healthy.

Clinical trial eligibility criteria: eligible ages (years): 18.0-64.0,  Influenza Subject is healthy, as determined by medical history 2. Over 18 years of age and not yet 65 years old 3. Provides written informed consent 4. Able to attend all scheduled visits and to comply with all trial procedures 5. Women may be menopausal of 1 year or more or sugically sterile. Women of child-bearing potential must agree to be abstinent or to use a licensed form of barrier or hormonal contraception for the entire study period, and have a negative pregnancy test within 24 hours prior to vaccination  Breast-feeding 2. Receipt of an investigational drug, biologic or device in the 4 weeks preceding the trial vaccination 3. Planned participation in another clinical trial during the present trial period 4. History of Guillain-Barré Syndrome 5. Congenital or acquired immunodeficiency, immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months, or long-term systemic corticosteroid therapy 6. Hypersensitivity to any of the vaccine components (including eggs or egg products or thimerosol and gelatin) or history of a life-threatening reaction to the trial vaccine or a vaccine containing the same substances 7. Chronic illness that could interfere with trial conduct or completion 8. Blood or blood-derived products received in the past 3 months 9. Has received any inactivated vaccine within 2 weeks or live vaccine within 4 weeks prior to enrollment into this study 10. Vaccination planned within the 4 weeks following the trial vaccination 11. Known current HIV, hepatitis B (HBsAg) or hepatitis C infection or seropositivity 12. Prior vaccination against influenza within the past 6 months 13. Allergy shot in the 7-day period prior to enrollment and must not be scheduled to receive any allergy shots in the 7-day period after enrollment 14. On coumadin or heparin therapy or has known thrombocytopenia or bleeding disorder contraindicating vaccination 15. Subject deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized without his/her consent 16. Febrile illness temperature >= 37.5°C on Day 0, prior to enrollment and vaccination 17. Any condition, that, in the opinion of the investigator, would pose a health risk to the participant 18. History of alcohol or drug abuse in the last 5 years 19. Planned travel outside the US between vaccination and the second study visit 20. Presence of any active skin disease at the injection site that, in the opinion of the Investigator, would impact vaccine delivery or assessment of vaccination site