1. Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
2. Center of Scientific Excellence for Influenza Viruses, National Research Centre (NRC), Dokki, Giza, Egypt
3. Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
4. California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California, Davis, United States
5. Institute of Virology, Philipps University Marburg, Marburg, Germany