1. Center for Infectious Disease Research, formerly Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA.
2. Department of Global Health, University of Washington, Seattle, WA 98195, USA.
3. Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109–1024, USA.
4. Department of Laboratory Medicine, University of Washington, 1959 Northeast Pacific Street, NW150, Seattle, WA 98195–7110, USA.
5. Center for Emerging and Re-emerging Infectious Diseases and Department of Microbiology, University of Washington, 750 Republican Street, E630, Seattle, WA 98109, USA.