A Phase 2 Study to Evaluate Immune Responses of FluMist®

The primary objective of this study is to describe the level of serum antibody and cellular immune responses conferred by FluMist and TIV against influenza virus strains.

The primary objective of this study is to describe the level of serum antibody and cellular immune responses conferred by FluMist and TIV against antigenically matched and antigenically mismatched influenza virus strains.

The secondary objective of this study is to describe the safety of FluMist and TIV in subjects 12 to \<36 months of age.

Eligibility Criteria:
Inclusion Criteria:

* Male or female aged 12 to \<36 months (reached their 1st year but not yet reached their 3rd year birthday) at the time of randomization
* Written informed consent and HIPAA authorization obtained from the subject's legal representative
* Ability of the subject's legal representative to understand and comply with the requirements of the study
* Subject's legal representative available by telephone
* Ability to complete follow-up period of 180 days after final study vaccination as required by the protocol

Exclusion Criteria:

* History of hypersensitivity to any component of FluMist or TIV, including egg or egg products
* History of hypersensitivity to gentamicin
* Any known immunosuppressive condition or immune deficiency disease (including HIV infection), or ongoing receipt of any immunosuppressive therapy
* Household contact who is immunocompromised (participants should also avoid close contact with immunocompromised individuals for at least 21 days after each study vaccination)
* History of Guillain-Barré syndrome
* Any prior history of wheezing or asthma
* Acute febrile (≥100.0°F oral or equivalent) and/or clinically significant respiratory illness (e.g., cough or sore throat) within 72 hours prior to either study vaccination
* Use of aspirin or aspirin-containing products within the 30 days prior to randomization, or expected receipt through 180 days after final study vaccination
* Receipt of any prior influenza vaccine
* Use of anti-influenza medications (including amantadine, rimantadine, oseltamivir, and zanamivir) within 14 days prior to randomization, or expected receipt through 35 days after final study vaccination
* Administration of any live virus vaccine, other than measles, mumps, rubella, and varicella-containing vaccine(s), within 30 days prior to randomization, or expected receipt through 30 days after final study vaccination
* Administration of any inactivated (i.e., non-live) vaccine within 14 days prior to randomization, or expected receipt within 14 days before or 14 days after either study vaccination
* Receipt of any investigational agent within 30 days prior to randomization, or expected receipt through 180 days after final study vaccination (use of licensed agents for indications not listed in the package insert is permitted)
* Receipt of any blood product within 90 days prior to randomization, or expected receipt through 35 days after final study vaccination
* Family member or household contact who is an employee of the research center or otherwise involved with the conduct of the study
* Any condition that in the opinion of the investigator would interfere with evaluation of the vaccine or interpretation of study results