1. Department of Epidemiology, Emory University, Atlanta, Georgia, USA.
2. Department of Epidemiology, The George Washington University, Washington, District of Columbia, USA.
3. Department of Epidemiology and Biostatistics, Drexel University, Philadelphia, Pennsylvania, USA.
4. Department of Epidemiology, Harvard University, Boston, Massachusetts, USA.
5. Department of Systems, Populations and Leadership, University of Michigan, Ann Arbor, Michigan, USA.
6. Division of Allergy & Infectious Diseases, University of Washington, Seattle, Washington, USA.