1. Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
2. Department of Microbiology, Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
3. WHO Collaborating Centre for Reference and Research on Influenza, VIDRL, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia