1. From the Center for Biologics Evaluation and Research, Bethesda MD; National Cancer Institute, National Institutes of Health, Bethesda, Maryland; Kanazawa University School of Medicine, Kanazawa, Ishikawa, Japan; Saitama Children's Medical Center, Iwatsuki, Saitama, Japan; and the Infectious Disease Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.