1. Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
2. VGX Pharmaceuticals, Inc., The Woodlands, Texas 77381
3. Bioqual, Inc., Rockville, Maryland 20850
4. U.S. Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Vaccines Research and Review, Division of Viral Products, Bethesda, Maryland 20892