Influence of Prior Influenza Vaccination on Current Influenza Vaccine Effectiveness in Children Aged 1 to 5 Years oleh Kazuhiro Matsumoto, Wakaba Fukushima, Saeko Morikawa, Masashi Fujioka, Tohru Matsushita, Megumi Kubota, Yoshina Yagi, Yoshio Takasaki, Shizuo Shindo, Yuji Yamashita, Takato Yokoyama, Yumi Kiyomatsu, Satoshi Hiroi, Keiko Nakata, Akiko Maeda, Kyoko Kondo, Kazuya Ito, Tetsuo Kase, Satoko Ohfuji, Yoshio Hirota