VRC 308: An Open-Label Phase I Study of the Safety and Immunogenicity of an Investigational H1 DNA Influenza Vaccine, VRC-FLUDNA057-00-VP, in Healthy Adults 18-70 Years Old

Background: * Vaccines are substances used to try to create resistance (or immunity) to a disease and to prevent an infection. Researchers are testing a new DNA vaccine designed for a new type of influenza, often referred to as swine flu. The DNA vaccine will instruct the body to make a particular kind of influenza protein that the immune system will be able to recognize. * Researchers are interested in determining if the vaccine is safe and effective in humans, and would like to study the immune system's response to the vaccine. The vaccine will not give participants influenza; however, it may not be effective in preventing them from getting influenza at a later date. Objectives: * To evaluate the safety and tolerability of the VRC-FLUDNA057-00-VP influenza vaccine as administered to healthy adults. * To evaluate antibody responses to the new influenza vaccine. Eligibility: \- Healthy adults between the ages of 18 and 70. Design: * Participants will have seven planned clinic visits during this study (enrollment day and study weeks 1, 4, 8, 9, 12, and 32). * All participants will receive three injections of the test vaccine, given as individual doses on day 0, day 28, and day 56 of the study. The vaccine will be given in the upper arm muscle. * Injections will be given using a needleless system that delivers the vaccine through the skin by using the pressure of carbon dioxide to inject the vaccine through the skin and into the muscle. Participants will remain at the National Institutes of Health (NIH) Clinical Center for at least 30 minutes after the injection to be monitored for any reaction. * Participants will be asked to keep a 7-day diary card after each injection to record their physical reactions to the vaccine. * Participants will be asked to return to the NIH Clinical Center as requested by researchers for additional blood tests and other procedures, as required by the study.