About the Authors

Masayoshi Shinjoh

Contributed equally to this work with: Masayoshi Shinjoh, Norio Sugaya

Affiliations Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan, Center for Infectious Diseases and Infection Control, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan

Norio Sugaya

Contributed equally to this work with: Masayoshi Shinjoh, Norio Sugaya

sugaya-n@za2.so-net.ne.jp

Affiliation Department of Paediatrics, Keiyu Hospital, Yokohama, Kanagawa, Japan

Yoshio Yamaguchi

‡ These authors also contributed equally to this work.

Affiliation Department of Clinical Research, National Hospital Organization, Utsunomiya, Tochigi Medical Center, Tochigi, Japan

Yuka Tomidokoro

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Tokyo Metropolitan Ohtsuka Hospital, Toshima-ku, Tokyo, Japan

Shinichiro Sekiguchi

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan

Keiko Mitamura

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Eiju General Hospital, Taito-ku, Tokyo, Japan

Motoko Fujino

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Saiseikai Central Hospital, Minato-ku, Tokyo, Japan

Hiroyuki Shiro

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Yokohama Rosai Hospital, Yokohama, Kanagawa, Japan

Osamu Komiyama

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, National Hospital Organization, Tokyo Medical Center, Meguro-ku, Tokyo, Japan

Nobuhiko Taguchi

‡ These authors also contributed equally to this work.

Affiliation Department of Paediatrics, Keiyu Hospital, Yokohama, Kanagawa, Japan

Yuji Nakata

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Nippon Kokan Hospital, Kawasaki, Kanagawa, Japan

Naoko Yoshida

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Kyosai Tachikawa Hospital, Tachikawa, Tokyo, Japan

Atsushi Narabayashi

‡ These authors also contributed equally to this work.

Affiliation Department of Paediatrics, Kawasaki Municipal Hospital, Kawasaki, Kanagawa, Japan

Michiko Myokai

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Shizuoka City Shimizu Hospital, Shizuoka, Shizuoka, Japan

Masanori Sato

Current Address: Department of Pediatric Intensive Care, Nagano Children’s hospital, Azumino, Nagano, Japan

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Tokyo Dental College Ichikawa General Hospital, Ichikawa, Chiba, Japan

Munehiro Furuichi

Current Address: Division of Infectious Diseases, Department of Medical Subspecialties, National Center for Child Health and Development, Setagaya-ku, Tokyo, Japan

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Saitama City Hospital, Saitama, Saitama, Japan

Hiroaki Baba

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Fuji Heavy Industries Health Insurance Society Ota Memorial Hospital, Ota, Gunma, Japan

Hisayo Fujita

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Hiratsuka Kyosai Hospital, Hiratsuka, Kanagawa, Japan

Akihiro Sato

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Yokohama Municipal Citizen's hospital, Yokohama, Kanagawa, Japan

Ichiro Ookawara

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Japanese Red Cross Shizuoka Hospital, Shizuoka, Shizuoka, Japan

Kenichiro Tsunematsu

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Hino Municipal Hospital, Hino, Tokyo, Japan

Makoto Yoshida

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Sano Kousei General Hospital, Sano, Tochigi, Japan

Mio Kono

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, National Hospital Organization Saitama National Hospital, Wako, Saitama, Japan

Fumie Tanaka

‡ These authors also contributed equally to this work.

Affiliation Department of Pediatrics, Hiratsuka City Hospital, Hiratsuka, Kanagawa, Japan

Chiharu Kawakami

Affiliation Yokohama City Institute of Health, Yokohama, Kanagawa, Japan

Takahisa Kimiya

Affiliation Department of Pediatrics, Tokyo Metropolitan Ohtsuka Hospital, Toshima-ku, Tokyo, Japan

Takao Takahashi

Affiliation Department of Pediatrics, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan

Satoshi Iwata

Affiliations Center for Infectious Diseases and Infection Control, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan, Department of Infectious Diseases, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan

Keio Pediatric Influenza Research Group

Membership of the Keio Pediatric Influenza Research Group is listed in the Acknowledgments.

Competing Interests

Within 36 months, MS has received speakers' honoraria from Chugai, Shionogi, Daiichi Sankyo, Japan Vaccine, and Astellas; and grant support from Japan Vaccine outside of the submitted work. NS has received speakers' honoraria from Chugai, Shionogi, Daiichi Sankyo, GlaxoSmithKline, Astellas, Takeda, Mitsubishi Tanabe, and Denka Seiken. YY has received speaker's honorarium from Shionogi. KM has received speakers' honoraria from Shionogi, Daiichi Sankyo, Japan Vaccine, Takeda, Astellas, and Denka Seiken. TT has received speakers' honoraria from Japan Vaccine and Astellas; and grant support from Chugai and Shionogi outside of the submitted work. SI has received speakers' honoraria from Chugai, Shionogi, Daiichi Sankyo, GlaxoSmithKline, Japan Vaccine, Astellas, Takeda, and Denka Seiken; and grant support from Chugai, Shionogi, Daiichi Sankyo, GlaxoSmithKline, Japan Vaccine, Takeda, and Astellas outside of the submitted work. Other authors have no competing interests regarding this study. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: MS NS TT SI. Performed the experiments: YY YT SS KM M. Fujino HS OK NT YN NY AN MM MS M. Furuichi HB HF AS IO KT MY MK FT TK. Analyzed the data: MS NS YY YT TT SI. Contributed reagents/materials/analysis tools: NS CK. Wrote the paper: MS NS.