The worldwide HIV/AIDS epidemic may only be controlled through development of a safe and effective vaccine that will prevent HIV infection. This study will evaluate the safety and immunogenicity of an experimental adenovirus-vectored multiclade HIV vaccine, VRC-HIVADV014-00-VP, followed with or without a similarly structured DNA plasmid HIV vaccine, VRC-HIVDNA016-00-VP. The DNA in both vaccines codes for proteins from HIV subtypes A, B, and C, which together represent 90% of new HIV infections in the world. HIV uninfected volunteers will be recruited in the East African nations of Kenya, Tanzania, and Uganda.