Safety of and Immune Response to a Bird Flu Virus Vaccine (H9N2) in Healthy Adults (Study B)

Inclusion Criteria: * Born after 1968 * Good general health * Available for the duration of the study * Female participants must agree to use acceptable forms of contraception Exclusion Criteria: * Significant medical illness, physical examination findings, or urine or blood abnormalities * Clinically significant neurologic, heart, lung, liver, rheumatologic, autoimmune, or kidney disease * Behavioral, cognitive, or psychiatric disease that, in the opinion of the investigator, may interfere with the study * Previously enrolled in an H9N2 influenza vaccine study or in any other study of a bird flu vaccine * Positive for the H9N2 influenza A virus (serum hemagglutination inhibiting \[HI\] factor antibody titer greater than 1:8) * Medical, work, or family problems as a result of alcohol or illegal drug use within 12 months prior to study entry * History of severe allergic reaction or anaphylaxis * Current asthma or reactive airway disease within 2 years prior to study entry * History of Guillain-Barre syndrome * HIV-1 serotype positive * Hepatitis C virus (HCV) positive * Hepatitis B surface antigen positive * Known immunodeficiency syndrome * Use of corticosteroids or immunosuppressive drugs within 30 days prior to study entry. Participants who have used topical corticosteroids are not excluded. * Live vaccine within 4 weeks prior to study entry * Killed vaccine within 2 weeks prior to study entry * Absence of spleen * Blood products within 6 months prior to study entry * Current smoker unwilling to stop smoking for the duration of the study * Plans to travel to the Southern Hemisphere or Asia within 14 days prior to study entry * Plans to travel on a cruise ship within 14 days prior to study entry * Work in the poultry industry * Received an investigational agent within 30 days prior to study entry * Allergy to eggs or egg products * Purified protein derivative (PPD) positive (positive tuberculosis \[TB\] test) * Family member with immunodeficiency * Other condition that, in the opinion of the investigator, would affect participation in the study * Pregnancy or breastfeeding