 - Subjects who qualify for the Division of Microbiology and Infectious Diseases, NIAID, NIH DMID study 04-039, A Randomized, Double-Blind, Placebo-Controlled, Phase II Study to Assess the Safety and Efficacy of the Cytomegalovirus gBMF59 Vaccine in Preventing Systemic Cytomegalovirus Infection in Healthy Adolescent, will be eligible for the initial pre-vaccination blood draw. 