1. Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA
2. Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555, USA
3. Present affiliation: Johns Hopkins Center for Health Security, Johns Hopkins University, Baltimore, MD 21202, USA; Institute of Public Health Genetics, University of Washington, Seattle, WA 98195, USA
4. Present affiliation: Glenn Biggs Institute for Alzheimer’s & Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA
5. Present affiliation: School of Life Sciences, Keele University, Staffordshire ST5 5BG, UK
6. Institute for Human Infection and Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA