1 Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland; Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, New York.
2 Rega Institute for Medical Research, University of Leuven, Leuven, Belgium.
3 Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, New York.
4 Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland.