Study Plan: Fifteen volunteers will be enrolled and randomized in a 2:1 ratio to vaccine:control (10 DNA prime with rAd boost:5 PBS with FFB placebo). A Data and Safety Monitoring Board (DSMB) will review the study every 6 months. Subjects will be evaluated for safety and immunogenicity for 48 weeks, which is 24 weeks after the target date for the booster vaccination.