1 Institute of Virology and Immunology, Bern and Mittelhäusern, Switzerland; Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.
2 Department for Molecular & Medical Virology, Ruhr University Bochum, Bochum Germany.
3 Institute of Virology and Immunology, Bern and Mittelhäusern, Switzerland; Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
4 Institute of Medical Microbiology, University Hospital of Essen, Essen, Germany; Institute of Clinical Hygiene, Medical Microbiology and Infectiology, General Hospital, Nürnberg, Paracelsus Medical University, Nürnberg, Germany.