An individual's participation in the study will last approximately 90 days. All participants will receive two vaccinations approximately 4 - 8 weeks apart. After each vaccination, participants will remain in isolation at the study site for at least nine days or until rRT-PCR assays for influenza are negative for 2 consecutive days. A physical examination and nasal wash will occur each day during the isolation period. Blood collection will occur in isolation beginning on Day 7 until release. Follow-up outpatient visits are scheduled on Days 28 and 56 after the first vaccination and on Day 28 after the second vaccination. Follow-up visits will include serum collection, nasal wash, and interim medical history.