Affiliation: | National Institute of Infectious Diseases, Tokyo, Japan (I. Takayama, M. Shirakura, M. Nakauchi, S. Fujisaki, H. Takahashi, S. Nagata, T. Odagiri, M. Tashiro, T. Kageyama); ;Pasteur Institute, Ho Chi Minh City, Vietnam (N.T. Hieu, N.T. Long) |