More than 2 billion people living in tropical and subtropical regions of the world are at risk of dengue virus infection. Dengue viruses cause dengue fever, as well as the more severe dengue hemorrhagic fever/shock syndrome, and dengue virus infection is the leading cause of hospitalization and death in children in several tropical Asian countries. This study will evaluate the safety and immunogenicity of a live, attenuated dengue virus called rDEN3delta30/31‐7164.