Safety Study of Seasonal Influenza Vaccine by Jet Injection

Inclusion Criteria: * Age 18 and 49 years, inclusive * In good health as evidenced by screening evaluation within the 30 days prior to immunization. * Expressed interest and availability to fulfill the study requirements. * Signed, informed consent. * For women of child-bearing potential, agreement to avoid pregnancy for the 90 days following vaccination by use of effective birth control methods. * Agreement to refrain from taking any experimental drug or vaccine from Day minus 30 to Day 90 (from screening until the volunteer completes the study). Exclusion Criteria: * A known allergy to a component of the vaccine, including egg, egg products, chicken proteins, formaldehyde, gentamicin sulfate, or sodium deoxycholate. * A positive urine pregnancy test in the 24 hours prior to vaccination. (A negative urine pregnancy test is required within the 24 before vaccination for all women who have not had a hysterectomy or are not at least 1 year post-menopausal) * A woman who is breastfeeding. * Any current medical illness that might jeopardize the volunteer's safety or interfere with the interpretation of the study results. These include, but are not limited to the following: cancer; immunodeficiency; bleeding disorder. * Any underlying medical condition for which influenza vaccination is recommended: chronic heart or lung conditions, including asthma; metabolic diseases; kidney disease; blood disorder (such as sickle cell anemia); weakened immune systems, including HIV/AIDS. * Resident of nursing homes and long term care facility. * Health care worker involved in direct patient care. * Any current illness requiring daily medication, except for vitamins, contraceptives, topical medications, antihistamines, antacids and other reflux medications, smoking cessation medications, headache medications that do not have antipyretic activity, nasal allergy medications, ophthalmologic and otic medications, psychiatric medications for well-controlled conditions such as depression or anxiety, and thyroxine for stable, inactive hypothyroidism. Volunteers may not take daily oral, nasal, inhaled, or parenteral steroids or non-steroidal anti-inflammatory medications. Medications other than those mentioned above will require approval from the PI, the sponsor, and the medical monitor. * Any use of antibiotics in the 7 days before enrollment. * Vital signs that are abnormal and thought by the investigator to increase the risk to the volunteer. Mild elevations or depressions of blood pressure or heart rate may be allowed. * Current alcohol or illicit drug dependence. * History of receipt of an influenza vaccine in the 2008-2009 and/or 2009-2010 season * History of Guillain-Barré Syndrome * Failure to pass the written exam; a passing score is 70% or greater. * Receipt of an experimental agent (e.g., a vaccine or medication) within the 30 days prior to enrollment or the expectation of receipt of an experimental agent while participating in this study. * Receipt of a live, attenuated vaccine within the 30 days prior to enrollment. * Receipt of a subunit or killed vaccine within the 14 days prior to enrollment. * Receipt of a blood product, including immunoglobulin, in the 90 days prior to enrollment. * Oral temperature \> 37.7 degrees C or other acute illness occurring prior to inoculation on the day of vaccination. (This will lead to postponement of enrollment, not exclusion from the trial. Mild resolving illnesses may be allowed at the discretion of the investigator) * Anything that, in the opinion of the investigator, will compromise the participation of the volunteer with respect to his/her rights or risks.