Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland SIB Swiss Institute of Bioinformatics, Basel, Switzerland.|Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland SIB Swiss Institute of Bioinformatics, Basel, Switzerland.|Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland Institute of Medical Virology.|Swiss National Center for Retroviruses, Institute of Medical Virology, University of Zurich, Zurich 8057, Switzerland.|Laboratory of Virology, Division of Infectious Diseases, Geneva University Hospital, Geneva, Switzerland.|Department of Biomedicine-Petersplatz, University of Basel, Basel, Switzerland.|Division of Immunology and Allergy, University Hospital Lausanne, Lausanne, Switzerland.|Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland Institute of Medical Virology.|Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland SIB Swiss Institute of Bioinformatics, Basel, Switzerland.|Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland SIB Swiss Institute of Bioinformatics, Basel, Switzerland.