1Influenza Virus Research Center, National Institute of Infectious Diseases, Tokyo, Japan
2Eiken Chemical Co., Ltd, Tokyo, Japan
3Division of Microbiology, Osaka Institute of Public Health, Osaka, Japan
4Aizenbashi Hospital, Osaka, Japan
5Nakano Children’s Hospital, Osaka, Japan
6Nishi-Tokyo Central General Hospital, Tokyo, Japan
7Department of Pediatrics, Showa General Hospital, Tokyo, Japan
8Asai Children’s Clinic, Osaka, Japan
© The Author(s) 2020
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