Primary Outcome Measures:
- Safety, defined as the frequency of vaccine-related reactogenicity events that occur during the acute monitoring (inpatient) phase of the study [ Time Frame: Daily for 9 days after vaccination ] [ Designated as safety issue: Yes ]
- Immunogenicity, determined by anti-H7N3 antibody titer [ Time Frame: Before the first vaccination, 28 days after the first vaccination but before the second vaccination, and 28 days after the second vaccination ] [ Designated as safety issue: No ]
- Quantifying the amount of vaccine virus shed by each recipient; and determining the amount of serum and nasal wash antibody induced by the vaccine [ Time Frame: Daily for 9 days after vaccination ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- To determine the number of vaccinees infected with the vaccine virus [ Time Frame: Daily for 8 days after each vaccination ] [ Designated as safety issue: No ]
- To determine the phenotypic stability of the vaccine virus [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
- To determine whether immunogenicity is enhanced by a second dose of vaccine [ Time Frame: At study completion ] [ Designated as safety issue: No ]
- To evaluate T-cell mediated and innate immune responses against the vaccine virus [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
- To develop a serum bank to evaluate future H7 influenza vaccines [ Time Frame: Throughout study ] [ Designated as safety issue: No ]
The current pandemic risk associated with avian influenza H7N3 infection is significant as an increasing number of humans are infected. H7 influenza transmission usually 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 between 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 AI virus vaccine, H7N3 (6-2) AA ca Recombinant (A/chicken/British Columbia/CN-6/2004 x A/Ann Arbor/6/60 ca).
This study will last approximately 90 days. Participation in this study includes two 12-day hospital stays 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, vital signs measurement, and a nasal wash will occur daily following each vaccination until discharge. Participants will be discharged after three consecutive nasal washes on or after Day 6 are negative. Blood and urine collection will occur at selected timepoints throughout the study. A follow-up outpatient visit will occur approximately 4 weeks following each vaccination.