VRC-300 (NIH 03-I-0285) was approved by the NIAID IRB. Through this protocol, the VRC has initiated recruitment of healthy, HIV-negative subjects for a clinical trial of an investigational Ebola vaccine trial. The protocol may also be used in the future to recruit and screen for vaccine studies for infectious diseases other than HIV. The results of these screening studies will be used to determine if the subject meets eligibility requirements for participation in Phase I trials of preventative vaccines. Educational materials on vaccines are reviewed with and provided to subjects before enrollment into a study. Some of these vaccine studies will be part of the VRC Biodefense agenda.