1. Department of Virology, Tohoku University Graduate School of Medicine, Sendai, Japan
2. Virology Department, Research Institute for Tropical Medicine, Muntinlupa, Philippines
3. Tohoku‐RITM Collaborating Research Center for Emerging and Reemerging Infectious Diseases, Muntinlupa, Philippines
4. World Health Organization‐Regional Office for the Western Pacific, Manila, Philippines