Screening of Volunteers for Clinical Trials of Investigational or Licensed Vaccines or Antiviral Products

Background: \- Vaccines and antiviral therapies help prevent and treat diseases. Researchers need a group of healthy volunteers for clinical trials. Clinical trials are studies that test these vaccines and therapies in people. Objective: \- To screen volunteers for clinical trials for investigational or licensed vaccines or drugs to treat or prevent virus infections. Eligibility: \- Healthy adults age 18 or older. Design: * Participants will be asked questions about their health history, including sexual activity and drug use. They will give blood samples. They may have a physical exam. They may give a urine sample. * Participants may have the inside of their nose either swabbed or washed with some fluid. The fluid will be collected. They may give a stool sample. * Participants may have an electrocardiogram. Soft, sticky patches will be attached to participants chest, arms, and legs. They will lie still on a table while the patches detect the heart s electrical signals. A machine will record these signals. * Participants may have lung function tests. These tests measure the volume of air moving in and out of the lungs. Participants will forcibly blow air into a machine. * Participants will be told if any tests show a medical problem. * If a participant is eligible and decides to join an investigational clinical trial, researchers will explain the study and the risks involved. Participants will sign a separate consent for that clinical trial.