1. Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio 45229, United States
2. Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
3. Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
4. Departments of Medicine and Microbiology and Immunology Emeritus, Stanford University School of Medicine, Stanford, California 94305, United States
5. Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229, United States