Patient description: A 67-year-old healthy woman came to the clinic to have her flu shot in early October. She works at a rehab center and has no underlying disease. It is her first vaccination this year. she is menopausal and has 4 children. She does not some. She takes daily multivitamins and anti-hypertensive drugs. She exercises regularly for 30 minutes a day at least 5 days a week. She has no allergies to any food or drugs.

Clinical trial eligibility criteria: eligible ages (years): 12.0-999.0,  Cough Sore Throat Nasal Congestion Headache Fever Seasonal Influenza Age ≥12 years of age, male or female Able to provide informed consent, or for whom consent may be provided by guardian, unless informed consent provided by a guardian or a legally authorized representative is not consistent with applicable local or ethical concerns, procedures, directives and/or guidelines Subject must have at least one of the following clinical presentations at Screening: 1. Oral temperature ≥ 38.0 °C (≥100.4 °F), ≥38.6°C (≥101.4 °F) tympanic or rectal OR 2. Oxygen saturation <92%, OR 3. Two out of the following three vital signs: Respiration rate >24/minute, Heart rate >100/minute, Systolic BP <90 mmHg Presence of at least one respiratory symptom (cough, sore throat, or nasal congestion) of any severity (mild, moderate, or severe) Presence of at least one constitutional symptom (headache, myalgia, feverishness, or fatigue) of any severity (mild, moderate, or severe) Onset of illness no more than 72 hours before presentation. Note: Time of onset of illness is defined as the earlier of either (1) the time when the temperature was first measured as elevated, OR (2) the time when the subject experienced the presence of at least one respiratory symptom AND the presence of at least one constitutional symptom Either: Severity of illness that, in the Investigator's judgment, justifies hospitalization of the subject for supportive care. OR Presence of one or more of the following factors: Age ≥60 years. Presence of chronic obstructive pulmonary disease (COPD) or other chronic lung disease requiring daily pharmacotherapy. Current history of congestive heart failure or angina. Presence of diabetes mellitus, clinically stable or unstable. Transcutaneous oxygen saturation <94% without supplemental oxygen for at least 5 minutes, or a medically significant decrease in oxygen saturation from an established baseline value (an investigative site at altitude >2000 ft above sea level will utilize different for oxygen saturation). History of chronic renal impairment not requiring peritoneal dialysis. Serum creatinine > 2.0 mg/dL or > 177 μmol/L Diagnosis of Influenza by satisfying one of the following: 1. Clinical Influenza with Positive Diagnostic Test. Subjects who have a positive rapid antigen test (RAT) for influenza A and/or influenza B (using a Sponsor-approved test kit), or positive test (using other methodology) for influenza A and/or B virus antigen or RNA performed in a clinical laboratory at the screening/enrollment evaluation are eligible for enrollment. OR 2. Clinical Influenza with Negative Rapid Antigen Test (RAT). Subjects with a negative RAT test may be enrolled once the site has been approved by the Sponsor to enroll such subjects, based on documentation of an outbreak of influenza in the community. An influenza outbreak may be documented in the catchment area of the hospital via one of the following methods: 1) local confirmation of influenza A or B infection in the current influenza season by a) the institution's local laboratory, or b) the local public health system, or c) the national public health system, or d) a laboratory of a recognized multinational influenza surveillance scheme such as the European Influenza Surveillance Network (EISN); 2) prior enrollment of a RAT positive subject into this study at the same institution in the current influenza season  Subjects who have been hospitalized for greater than 24 hours (not including time spent in the Emergency Department) Treatment with any dose(s) of rimantadine, amantadine, ribavirin, zanamivir, or oseltamivir in the previous 7 days Blood platelet count of < 20 x 109/L at the time of the screening evaluation Serum bilirubin > 6 mg/dL or > 105 μmol/L at time of screening evaluation Serum ALT or AST > 5 times the upper limit of normal at time of screening evaluation Congestive heart failure of NYHA Class III or Class IV functional status Serum creatinine > 5.0 mg/dL or > 500 μmol/L at time of screening evaluation Subjects who require peritoneal dialysis Altered neurologic status as defined by a Glasgow Coma Score of ≤ 9, unless medically induced Females who are pregnant (positive urine or serum pregnancy test at screening evaluation) or breastfeeding