1. Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, Georgia , USA
2. Cherokee Nation Assurance , Arlington, Virginia, contracting agency to the Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Diseases Control and Prevention, Atlanta, Georgia , USA
3. Atlanta VA Medical Center , Atlanta, Georgia , USA
4. Emory University School of Medicine and Rollins School of Public Health , Atlanta, Georgia , USA
5. James J. Peters VA Medical Center , Bronx, New York , USA
6. Icahn School of Medicine at Mt. Sinai , New York, New York , USA
7. Infectious Diseases Section, Michael E. DeBakey VA Medical Center and Department of Medicine, Baylor College of Medicine , Houston, Texas , USA
8. VA Greater Los Angeles Healthcare System , Los Angeles, California , USA
9. David Geffen School of Medicine at UCLA , Los Angeles, California , USA
10. Department of Veterans Affairs, Public Health Surveillance and Research , Washington DC , USA
11. VA Palo Alto Health Care System , Palo Alto California , USA
12. Stanford University , Stanford, California , USA