1. T. W. Baba, Division of Newborn Medicine, Department of Pediatrics, Tufts University School of Medicine, Boston, MA 02111, and Laboratory of Viral Pathogenesis, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
2. A. M. Trichel, L. N. Martin, M. Murphey-Corb, Tulane Regional Primate Research Center, Tulane University, Covington, LA 70433, USA.
3. L. An, V. Liska, R. M. Ruprecht, Laboratory of Viral Pathogenesis, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.