1. Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA
2. Institute of Virology, Technical University of Munich, School of Medicine/Helmholtz Zentrum München, Munich, Germany
3. German Center for Infection Research (DZIF), Partner Site Munich, Munich, Germany
4. Division of Infectious Diseases and Global Public Health, University of California, San Diego, La Jolla, California, USA