1. Vaccine and Gene Therapy Institute and Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, OR 97006, USA.
2. AIDS and Cancer Virus Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD 21702, USA.
3. Population Sciences and Computational Biology Programs, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
4. Division of Infection and Immunity, Roslin Institute, University of Edinburgh, Edinburgh, UK.