1. Center for the Study of Hepatitis C, Rockefeller University, New York, NY 10021, USA.
2. Center for Vaccines and Immunity, Columbus Children's Research Institute, 700 Children's Drive, W503, Columbus, OH 43205, USA.
3. Centocor, Malvern, PA 19355, USA.
4. Department of Virology and Immunology, Southwest Foundation for Biomedical Research, San Antonio, TX 78227, USA.
5. Department of Pediatrics, College of Medicine and Public Health, Ohio State University, Columbus, OH 43205, USA.