PLoS ONE (Jan 2021)

Influenza vaccine effectiveness against influenza A in children based on the results of various rapid influenza tests in the 2018/19 season.

  • Masayoshi Shinjoh,
  • Norio Sugaya,
  • Yoshio Yamaguchi,
  • Ichiro Ookawara,
  • Yuji Nakata,
  • Atsushi Narabayashi,
  • Munehiro Furuichi,
  • Naoko Yoshida,
  • Akinobu Kamei,
  • Yuu Kuramochi,
  • Akimichi Shibata,
  • Motoko Shimoyamada,
  • Hisataka Nakazaki,
  • Naohiko Maejima,
  • Erika Yuasa,
  • Eriko Araki,
  • Naonori Maeda,
  • Takuma Ohnishi,
  • Mitsuhiro Nishida,
  • Nobuhiko Taguchi,
  • Makoto Yoshida,
  • Kenichiro Tsunematsu,
  • Meiwa Shibata,
  • Yasuhiro Hirano,
  • Shinichiro Sekiguchi,
  • Chiharu Kawakami,
  • Keiko Mitamura,
  • Takao Takahashi

DOI
https://doi.org/10.1371/journal.pone.0249005
Journal volume & issue
Vol. 16, no. 3
p. e0249005

Abstract

Read online

During influenza epidemics, Japanese clinicians routinely conduct rapid influenza diagnostic tests (RIDTs) in patients with influenza-like illness, and patients with positive test results are treated with anti-influenza drugs within 48 h after the onset of illness. We assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children (6 months-15 years old, N = 4243), using a test-negative case-control design based on the results of RIDTs in the 2018/19 season. The VE against influenza A(H1N1)pdm and A(H3N2) was analyzed separately using an RIDT kit specifically for detecting A(H1N1)pdm09. The adjusted VE against combined influenza A (H1N1pdm and H3N2) and against A(H1N1)pdm09 was 39% (95% confidence interval [CI], 30%-46%) and 74% (95% CI, 39%-89%), respectively. By contrast, the VE against non-A(H1N1)pdm09 influenza A (presumed to be H3N2) was very low at 7%. The adjusted VE for preventing hospitalization was 56% (95% CI, 16%-77%) against influenza A. The VE against A(H1N1)pdm09 was consistently high in our studies. By contrast, the VE against A(H3N2) was low not only in adults but also in children in the 2018/19 season.