Over the past decade, avian influenza (AI) has become a major health concern. The development of a safe and effective vaccine against H5N1 infection is important. The purpose of this study is to determine the safety of a new AI vaccine in healthy adults.

According to the World Health Organization, the current pandemic risk associated with avian influenza H5N1 infection is serious, as an increasing number of humans are infected. Currently, H5N1 influenza transmission occurs in humans when they are exposed through direct contact to infected poultry or surfaces and objects contaminated by infected poultry feces. A pandemic occurs when a new influenza subtype emerges that infects humans, causes serious illness, and spreads easily among humans. The development of a safe and effective vaccine is necessary, should a pandemic occur. The purpose of this study is to evaluate the safety and immunogenicity of a live, attenuated A1 virus vaccine, H5N1 (6-2) AA ca Recombinant (A/Hong Kong/213/2003 x A/AnnArbor/6/60 ca).

This study will last approximately 16 weeks. Participation in this study includes a hospital stay in an isolation unit at the Johns Hopkins Bayview Medical Center. All participants will receive two doses of vaccine in nasal spray form, at study entry and sometime between 4 and 8 weeks after initial vaccination. Participants will be admitted to the isolation unit 2 days prior to each vaccination. A targeted physical exam will occur daily following each vaccination until discharge. Participants will not be discharged until nasal washes are negative. Vital signs measurement will be done at least twice daily for the duration of the inpatient stay. A follow-up outpatient visit will occur approximately 4 weeks following each vaccination. Blood and urine collection will occur at selected timepoints throughout the study.

Inclusion Criteria:

• Good general health
• Available for the duration of the study
• Willing to use acceptable forms of contraception for the duration of the study

Exclusion Criteria:

• Clinically significant neurologic, heart, lung, liver, rheumatologic, autoimmune, or kidney disease
• Behavioral or cognitive impairment or psychiatric disease that, in the opinion of the investigator, may affect study participation
• Medical, work, or family problems as a result of alcohol or illicit drug use within 12 months prior to study entry
• Previously enrolled in an H5N1 influenza vaccine trial or in any study of an avian influenza vaccine
• Seropositive to the H5N1 influenza A virus (serum hemagglutination inhibitor [HI] titer greater than 1:8)
• Illegal drug use or dependency determined by urine test
• History of severe allergic reaction
• Allergy to oseltamivir
• Asthma or reactive airways disease within 2 years prior to study entry
• History of Guillain-Barre syndrome
• HIV infected
• Hepatitis C virus infected
• Positive for hepatitis B surface antigen (HBsAg)
• Known immunodeficiency syndrome
• Use of corticosteroid or immunosuppressive drugs within 30 days prior to vaccination. Participants who have used topical corticosteroids are not excluded.
• Live vaccines within 4 weeks prior to study vaccination
• Killed vaccines within 2 weeks prior to study vaccination
• Absence of spleen
• Blood products within 6 months prior to study vaccination
• Current smoker unwilling to stop smoking for the duration of the study
• Have traveled to the Southern Hemisphere or Asia within 14 days prior to study vaccination
• Have traveled on a cruise ship within 14 days prior to study vaccination
• Work in the poultry industry
• Other investigational vaccine or drug within 30 days prior to study vaccination
• Allergy to eggs or egg products
• Purified protein derivative (PPD) positive (positive tuberculosis [TB] test)
• Have family member with immunodeficiency-related condition
• Other condition that, in the opinion of the investigator, may interfere with the study
• Pregnancy or breastfeeding