University of Nebraska Medical Center, Omaha, NE, USA. Electronic address: akalil@unmc.edu. Emory University, Atlanta, GA, USA. University of Texas Health San Antonio, University Health System, and the South Texas Veterans Health Care System, San Antonio, TX, USA. University of Alabama at Birmingham, Birmingham, AL, USA. University of Utah, Salt Lake City, UT, USA. University of Texas Southwestern Medical Center, Parkland Health & Hospital System, Dallas, TX, USA; UT Southwestern Medical Center, Parkland Health and Hospital System, Dallas, TX, USA. Duke University, Durham, NC. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico. University of Minnesota Medical School, Minneapolis, MN, USA. Instituto Nacional de Enfermedades Respiratorias, Mexico City, Mexico. University of California San Francisco, San Francisco, CA, USA. University of New Mexico Health Sciences Center, Albuquerque, NM, USA. University of Virginia, Charlottesville, VA, USA. University of Florida, Gainesville, FL, USA. Cedars Sinai Medical Center, Los Angeles, CA, USA. Seoul National University Hospital, Seoul, Korea. Baylor College of Medicine, Houston, TX, USA. Kaiser Permanente Northwest, Portland, OR, USA. Pennsylvania State Health Milton S Hershey Medical Center, Hershey, PA, USA. Carver College of Medicine, University of Iowa, Iowa City, IA, USA. National Center for Global Health and Medicine, Tokyo, Japan. University of California San Diego, La Jolla, CA, USA. Baylor Scott & White Health, Dallas, TX, USA. Denver Health and Hospital Authority, Denver, CO, USA. Massachusetts General Hospital, Boston, MA, USA. Houston Methodist, Houston, TX, USA. Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA. University of Rochester and Rochester Regional Health, Rochester, NY, USA. Providence Sacred Heart Medical Center, Spokane, WA, USA. Evergreen Health Medical Center, Kirkland, WA, USA. Seoul National University Bundang Hospital, Seongnam, Korea. University of Nebraska Medical Center, Omaha, NE, USA. Naval Medical Center, San Diego, CA, USA; Infectious Disease Clinical Research Program, Uniformed Services University of the Health Sciences, Bethesda, MD, USA. EMD Serono Research & Development Institute, Billerica, MA, USA. The Emmes Company, Rockville, MD, USA. Clinical Monitoring Research Program Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD, USA. National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD.