Influenza is a virus infection that causes sickness from the nose to the lungs. It is thought that type 1 interferon (a protein that helps the immune system fight viruses) will make flu vaccines more effective. This study will determine if type 1 interferon added to a specific flu vaccine will help the immune system of healthy adults fight off infection better than vaccine alone. Ninety volunteers, ages 18-40, will participate in this study. They will attend 3 study visits and have a final follow-up study visit, email, or phone call about six months after the vaccination. Volunteers will receive a single dose of study vaccine sprayed into the nose. Study procedures including blood samples and nasal washes (the inside of the nose is washed out) will be collected to evaluate immune system responses.