1. Department of Microbiology & Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
2. The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
3. Infectious Disease Clinical Research Program, Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
4. Department of Pediatrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA