681Influenza vaccine effectiveness in young Japanese children over five seasons

Autor: Satoshi Hiroi, Akiko Maeda, Tohru Matsushita, Shizuo Shindo, Yumi Kiyomatsu, Tetsuhisa Takechi, Wakaba Fukushima, Takato Yokoyama, Kazuya Ito, Kyoko Kondo, Megumi Kubota, Yoshina Yagi, Yoshio Hirota, K. Matsumoto, Saeko Morikawa, Yoshio Takasaki, Yuji Yamashita, Satoko Ohfuji, Tetsuo Kase, Keiko Nakata, Masashi Fujioka
Rok vydání: 2021
Předmět:
Zdroj: International Journal of Epidemiology. 50
ISSN: 1464-3685
0300-5771
DOI: 10.1093/ije/dyab168.209
Popis: Background Evidence is limited for influenza vaccine effectiveness (VE) against laboratory-confirmed influenza among young children. Using test-negative design (a modified case-control study) which minimizes confounding by health care-seeking behavior and misclassification of diseases, we aimed to monitor influenza VE among young children in Japan where all approved influenza vaccines are egg-propagated, inactivated formulations (IIV). Methods For seasons spanning 2013-14 to 2017-18 in Osaka and Fukuoka Prefectures, Japan, we employed prospective, active, and systematic recruitment of children aged Results We analyzed 4,614 subjects including 1,917 cases. VEs of IIV with 2 doses approximated 50%, ranging from 41% (95% confidence interval [CI]: 14 % to 60%) in 2016-17 season to 63% (95% CI: 45% to 76%) in 2017-18 season. Significant VEs were also shown for predominant circulating strains every season, irrespective of their antigenic match to vaccine strains (56% and 65% for A[H1N1]pdm, 37% and 50% for A[H3N2], and 60% for B[Yamagata]). Conclusions IIV provided modest and significant protection against laboratory-confirmed influenza in young Japanese children. Key messages Test-negative design is useful for monitoring influenza VE.
Databáze: OpenAIRE
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