TY - JOUR
T1 - Trends in effectiveness of inactivated influenza vaccine in children by age groups in seven seasons immediately before the COVID-19 era
AU - Shinjoh, Masayoshi
AU - Furuichi, Munehiro
AU - Kobayashi, Hisato
AU - Yamaguchi, Yoshio
AU - Maeda, Naonori
AU - Yaginuma, Mizuki
AU - Kobayashi, Ken
AU - Nogayama, Taisuke
AU - Chiga, Michiko
AU - Oshima, Mio
AU - Kuramochi, Yuu
AU - Yamada, Go
AU - Narabayashi, Atsushi
AU - Ookawara, Ichiro
AU - Nishida, Mitsuhiro
AU - Tsunematsu, Kenichiro
AU - Kamimaki, Isamu
AU - Shimoyamada, Motoko
AU - Yoshida, Makoto
AU - Shibata, Akimichi
AU - Nakata, Yuji
AU - Taguchi, Nobuhiko
AU - Mitamura, Keiko
AU - Takahashi, Takao
N1 - Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/5/11
Y1 - 2022/5/11
N2 - Background: We have reported the vaccine effectiveness of inactivated influenza vaccine in children aged 6 months to 15 years between the 2013/14 and 2018/19 seasons. Younger (6–11 months) and older (6–15 years old) children tended to have lower vaccine effectiveness. The purpose of this study is to investigate whether the recent vaccine can be recommended to all age groups. Methods: The overall adjusted vaccine effectiveness was assessed from the 2013/14 until the 2020/21 season using a test-negative case-control design based on rapid influenza diagnostic test results. Vaccine effectiveness was calculated by influenza type and by age group (6–11 months, 1–2, 3–5, 6–12, and 13–15 years old) with adjustments including influenza seasons. Results: A total of 29,400 children (9347, 4435, and 15,618 for influenza A and B, and test-negatives, respectively) were enrolled. The overall vaccine effectiveness against influenza A, A(H1N1)pdm09, and B was significant (44% [95% confidence interval (CI), 41–47], 63% [95 %CI, 51–72], and 37% [95 %CI, 32–42], respectively). The vaccine was significantly effective against influenza A and B, except among children 6 to 11 months against influenza B. The age group with the highest vaccine effectiveness was 1 to 2 years old with both influenza A and B (60% [95 %CI, 55–65] and 52% [95 %CI, 41–61], respectively). Analysis for the 2020/21 season was not performed because no cases were reported. Conclusions: This is the first report showing influenza vaccine effectiveness by age group in children for several seasons, including immediately before the coronavirus disease (COVID-19) era. The fact that significant vaccine effectiveness was observed in nearly every age group and every season shows that the recent vaccine can still be recommended to children for the upcoming influenza seasons, during and after the COVID-19 era.
AB - Background: We have reported the vaccine effectiveness of inactivated influenza vaccine in children aged 6 months to 15 years between the 2013/14 and 2018/19 seasons. Younger (6–11 months) and older (6–15 years old) children tended to have lower vaccine effectiveness. The purpose of this study is to investigate whether the recent vaccine can be recommended to all age groups. Methods: The overall adjusted vaccine effectiveness was assessed from the 2013/14 until the 2020/21 season using a test-negative case-control design based on rapid influenza diagnostic test results. Vaccine effectiveness was calculated by influenza type and by age group (6–11 months, 1–2, 3–5, 6–12, and 13–15 years old) with adjustments including influenza seasons. Results: A total of 29,400 children (9347, 4435, and 15,618 for influenza A and B, and test-negatives, respectively) were enrolled. The overall vaccine effectiveness against influenza A, A(H1N1)pdm09, and B was significant (44% [95% confidence interval (CI), 41–47], 63% [95 %CI, 51–72], and 37% [95 %CI, 32–42], respectively). The vaccine was significantly effective against influenza A and B, except among children 6 to 11 months against influenza B. The age group with the highest vaccine effectiveness was 1 to 2 years old with both influenza A and B (60% [95 %CI, 55–65] and 52% [95 %CI, 41–61], respectively). Analysis for the 2020/21 season was not performed because no cases were reported. Conclusions: This is the first report showing influenza vaccine effectiveness by age group in children for several seasons, including immediately before the coronavirus disease (COVID-19) era. The fact that significant vaccine effectiveness was observed in nearly every age group and every season shows that the recent vaccine can still be recommended to children for the upcoming influenza seasons, during and after the COVID-19 era.
KW - COVID-19 era
KW - Children
KW - Influenza
KW - Test-negative design
KW - Vaccine
KW - Vaccine effectiveness
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U2 - 10.1016/j.vaccine.2022.04.033
DO - 10.1016/j.vaccine.2022.04.033
M3 - Article
C2 - 35450780
AN - SCOPUS:85128669911
SN - 0264-410X
VL - 40
SP - 3018
EP - 3026
JO - Vaccine
JF - Vaccine
IS - 22
ER -