Evaluation of the Safety and Immunogenicity of a Live Attenuated Virus Vaccine for the Prevention of H2N3 Influenza

Inclusion Criteria: * In general good health, without significant medical illness, physical examination findings, or significant laboratory abnormalities as determined by the investigator * Agree to storage of blood specimens for future research * Available for the duration of the trial * Willing to participate in the study as evidenced by signing the informed consent document * Female participants must agree to use effective birth control methods for the duration of the study. More information on this criterion can be found in the protocol. Exclusion Criteria: * Pregnant or breastfeeding * Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease by history, physical examination, and/or laboratory studies including urine testing. Clinically significant alanine aminotransferase (ALT) levels, as determined by the principal investigator (PI), will be exclusionary at baseline, prior to vaccination. * Behavioral or cognitive impairment or psychiatric disease that in the opinion of the investigator affects the ability of the participant to understand and cooperate with the study procedures * Previous enrollment in an H2 influenza vaccine trial or in any study of an avian influenza vaccine * Seropositive to the H2N3 influenza A virus (serum HAI titer greater than 1:8) * Positive urine drug toxicology test indicating narcotic use/dependency * Have medical, occupational, or family problems as a result of alcohol or illicit drug use during the 12 months prior to study entry * Other condition that, in the opinion of the investigator, would jeopardize the safety or rights of a person participating in the trial or would render the person unable to comply with the study procedures * History of anaphylaxis * Allergy to oseltamivir as determined by participant report * Current diagnosis of asthma or reactive airway disease (within the 2 years prior to study entry) * History of Guillain-Barré Syndrome * Positive ELISA and confirmatory Western blot tests for human immunodeficiency virus-1 (HIV-1) * Positive ELISA and confirmatory test (e.g., recombinant immunoblot assay) for hepatitis C virus (HCV) * Positive hepatitis B virus surface antigen (HBsAg) by ELISA * Known immunodeficiency syndrome * Use of corticosteroids (excluding topical preparations) or immunosuppressive drugs within 30 days prior to vaccination * Receipt of a live vaccine within 4 weeks or a killed vaccine within 2 weeks prior to study vaccination * History of a surgical splenectomy * Receipt of blood or blood-derived products (including immunoglobulin) within 6 months prior to study vaccination * Current smoker unwilling to stop smoking for the duration of the study. More information on this criterion can be found in the protocol. * Travel to the Southern Hemisphere within 14 days prior to study vaccination * Travel on a cruise ship within 14 days prior to study vaccination * Receipt of another investigational vaccine or drug within 30 days prior to study vaccination * Allergy to eggs or egg products