Screening for LID Clinical Studies Unit Healthy Volunteer Protocols

Background: * The Laboratory of Infectious Diseases (LID) Clinical Studies Unit (CSU) enrolls healthy volunteers into clinical studies to study infectious diseases. * Viruses can be highly infectious and contagious. They cause considerable illness in the United States each year and a good example of this is influenza (the flu). The LID CSU performs clinical studies to learn about these viral infections and assist in the development of vaccines and treatments for the infections. These clinical studies include influenza "challenge studies" as well as natural history studies and phase I trials involving vaccines for viruses carried by mosquitos such as Zika or Dengue virus. * In influenza challenge studies studies, doctors expose a person to a flu virus. Then they study the flu through the body's natural healing process. This information will help to find better ways to prevent the flu and may also improve treatments for the flu. * Natural history studies and phase I trials of new vaccines are performed so the researchers can learn how some viral infections occur and if new vaccines are safe and potentially effective in preventing the infections. In some of these studies, participants experience insect bites with special clean (non-infected) insects (such as mosquitos) to better understand the role of insects in these infections. Objectives: \- To screen healthy volunteers for future CSU studies. Eligibility: \- Healthy people between the ages of 18 and 65 Design: * The 3- to 5-hour screening exam includes the following: * Medical history and physical exam * Standard blood tests including pregnancy, Hepatitis B and C, and HIV tests * Standard urine drug testing * Electrocardiogram (ECG) to test heart rhythm and function * Chest x-ray * Eligible volunteers are enrolled in the study for up to 1 year, until they take part in a CSU study or are found to be ineligible to participate. * Volunteers may withdraw from the study pool at any time.