Trends in effectiveness of inactivated influenza vaccine in children by age groups in seven seasons immediately before the COVID-19 era

Masayoshi Shinjoh, Munehiro Furuichi, Hisato Kobayashi, Yoshio Yamaguchi, Naonori Maeda, Mizuki Yaginuma, K. Kobayashi, Taisuke Nogayama, Michiko Chiga, Mio Oshima, Yuu Kuramochi, Go Yamada, Atsushi Narabayashi, Ichiro Ookawara, Mitsuhiro Nishida, Kenichiro Tsunematsu, Isamu Kamimaki, Motoko Shimoyamada, Makoto Yoshida, Akimichi Shibata, Yuji Nakata, Nobuhiko Taguchi, Keiko Mitamura, Takao Takahashi