1. Department of Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut 71516, Egypt
2. National Influenza Center, Robert Koch Institute, 13353 Berlin, Germany
3. Heinrich Pette Institute, Leibniz Institute for Experimental Virology, 20251 Hamburg, Germany
4. Department of Chest Diseases, Faculty of Medicine, Assiut University, Assiut 71516, Egypt