Inclusion Criteria:

• Male or female age 18 to 49 years, inclusive, on the day of randomization (reached his or her eighteenth year birthday but not yet reached his or her 50th year birthday) at the time of the dose of blinded investigational product
• Written informed consent and any locally required authorization obtained from the subject prior to performing any protocol-related procedures, including screening evaluations
• Females of child-bearing potential, (ie, unless surgically sterile [eg, bilateral tubal ligation, bilateral oophorectomy, or hysterectomy], has sterile male partner, is at least 1 year post-menopausal, or practices abstinence) must use an effective method of avoiding pregnancy (including oral, transdermal, or implanted contraceptives, intrauterine device, female condom with spermicide, diaphragm with spermicide, cervical cap, or use of a condom with spermicide by the sexual partner) for 30 days prior to the first dose of investigational product, and must agree to continue using such precautions for 60 days after the dose of investigational product. In addition, the subject must also have a negative urine or blood pregnancy test at screening and, if screening and Day 0 do not occur on the same day, on the day of vaccination prior to randomization. Investigator judgment is required to assess a female subject's capability of pregnancy.
• Healthy by medical history and physical examination OR presence of stable underlying chronic medical condition for which hospitalization has not been required in the previous year
• Able to complete follow-up period of 180 days post dose of vaccine as required by the protocol
• Subject available by telephone
• Able to understand and comply with the requirements of the protocol, as judged by the investigator

Exclusion Criteria:

• Any of the following would exclude the subject from participation in the study:
• Acute illness or evidence of significant active infection at randomization
• Fever ≥ 100.4°F (38°C) at randomization
• History of asthma
• Any drug therapy from 15 days prior to randomization or expected drug therapy through 30 days post dose with the exception of contraceptives or chronic medications that have been well tolerated and were not initiated and/or did not have a dosage change within 90 days of randomization.
• Previous medical history or evidence of an intercurrent illness that may compromise the safety of the subject in the study

• Current or expected receipt of immunosuppressive medications (inhaled and topical corticosteroids are permitted) including corticosteroids (≥ 20 mg/day of prednisone equivalent given daily or on alternate days for

  • 14 days) within a 30 day window around dose of investigational product Note: topical corticosteroids for uncomplicated dermatitis may be used throughout the study according to the judgment of the investigator; topical calcineurin inhibitors may be used in accordance with their package insert at entry and during study participation.
• Receipt of immunoglobulin or blood products within 90 days before randomization into the study or expected receipt during study participation
• Receipt of any investigational drug therapy or standard vaccine within 30 days before the dose of investigational product in this study through 30 days after the dose of investigational product (use of licensed agents for indications not listed in the package insert is permitted)
• Any known immunosuppressive condition or immune deficiency disease including known or suspected infection with human immunodeficiency virus (HIV)
• History of allergic disease or reactions likely to be exacerbated by any component of the investigational product including allergy to eggs, egg proteins, gentamicin, or gelatin or serious, life threatening, or severe reactions to previous influenza vaccinations
• History of Guillain-Barré syndrome
• Use of antiviral agents with activity against influenza virus (including amantadine, rimantadine, oseltamivir and zanamivir) within 30 days prior to dose of investigational product or anticipated use within 30 days after vaccination
• Known or suspected mitochondrial encephalomyopathy
• Lactating woman
• History of alcohol or drug abuse that, in the opinion of the investigator, would affect the subject's safety or compliance with study
• Any condition that, in the opinion of the investigator, would interfere with evaluation of the investigational product or interpretation of subject safety or study results
• Employees of the clinical study site or any other individuals involved with the conduct of the study, or immediate family members of such individuals Note: an individual who initially is excluded from study participation based on one or more of the above time-limited criteria may be reconsidered for enrollment once the condition has resolved as long as the subject continues to meet all other entry criteria.