Tweet
Vaccine. 2019 Jun 8. pii: S0264-410X(19)30747-9. doi: 10.1016/j.vaccine.2019.05.090. [Epub ahead of print]
Effectiveness of inactivated influenza vaccine in children by vaccine dose, 2013-18.
Shinjoh M1, Sugaya N2, Furuichi M3, Araki E4, Maeda N5, Isshiki K6, Ohnishi T7, Nakamura S8, Yamada G9, Narabayashi A10, Nishida M11, Taguchi N12, Nakata Y13, Yoshida M14, Tsunematsu K15, Shibata M16, Munenaga T17, Hirano Y18, Ookawara I19, Sekiguchi S3, Kobayashi Y20, Yamaguchi Y21, Yoshida N22, Mitamura K23, Takahashi T3; Keio Pediatric Influenza Research Group.
Author information
Abstract
OBJECTIVES:
We assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) by vaccine dose in children aged 6 months to 12 years for whom two doses are recommended in Japan to ascertain the appropriate vaccine doses.
METHODS:
VE was assessed according to a test-negative case-control design based on rapid influenza diagnostic test (RIDT) results. Children aged 6 months to 12 years with a fever ≥38 ?C who had received an RIDT in outpatient clinics of 24 hospitals were enrolled for all five seasons since 2013/14. VE by vaccine dose (none vs. once or twice, and once vs. twice) was analyzed.
RESULTS:
In the dose analysis, 20,033 children were enrolled. Both one- and two-dose regimens significantly reduced cases in preventing any influenza, influenza A, and influenza B, but there was no significant difference in adjusted VE between one- and two-dose regimens overall (adjusted OR, 0.560 [95% CI, 0.505-0.621], 0.550 [95% CI, 0.516-0.586]), 0.549 [95% CI, 0.517-0.583], and 1.014 [95% CI, 0.907-1.135], for none vs. once, none vs. twice, none vs. once or twice, and once vs. twice for any influenza, respectively). Both one- and two-dose regimens significantly reduced cases with any influenza and influenza A every season. Also, both regimens significantly reduced cases of any influenza, influenza A, and influenza B among children aged 1-12 years, especially among those aged 1-5 years. In the 2013/14, 2015/16, and 2016/17 seasons, however, only the two-dose regimen was significantly effective in preventing influenza B. Both one- and two-dose regimens significantly reduced cases involving hospitalization due to any influenza and influenza A.
CONCLUSIONS:
Both one- and two-doses regimens of IIV were effective in preventing influenza for children aged 6 months to 12 years. The two-dose regimen was more effective against influenza B in some seasons.
Copyright ? 2019 Elsevier Ltd. All rights reserved.
KEYWORDS:
Children; Effectiveness; Hospitalization; Influenza vaccine; Test-negative case control; Vaccine dose
PMID: 31186191 DOI: 10.1016/j.vaccine.2019.05.090
Effectiveness of inactivated influenza vaccine in children by vaccine dose, 2013-18.
Shinjoh M1, Sugaya N2, Furuichi M3, Araki E4, Maeda N5, Isshiki K6, Ohnishi T7, Nakamura S8, Yamada G9, Narabayashi A10, Nishida M11, Taguchi N12, Nakata Y13, Yoshida M14, Tsunematsu K15, Shibata M16, Munenaga T17, Hirano Y18, Ookawara I19, Sekiguchi S3, Kobayashi Y20, Yamaguchi Y21, Yoshida N22, Mitamura K23, Takahashi T3; Keio Pediatric Influenza Research Group.
Author information
Abstract
OBJECTIVES:
We assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) by vaccine dose in children aged 6 months to 12 years for whom two doses are recommended in Japan to ascertain the appropriate vaccine doses.
METHODS:
VE was assessed according to a test-negative case-control design based on rapid influenza diagnostic test (RIDT) results. Children aged 6 months to 12 years with a fever ≥38 ?C who had received an RIDT in outpatient clinics of 24 hospitals were enrolled for all five seasons since 2013/14. VE by vaccine dose (none vs. once or twice, and once vs. twice) was analyzed.
RESULTS:
In the dose analysis, 20,033 children were enrolled. Both one- and two-dose regimens significantly reduced cases in preventing any influenza, influenza A, and influenza B, but there was no significant difference in adjusted VE between one- and two-dose regimens overall (adjusted OR, 0.560 [95% CI, 0.505-0.621], 0.550 [95% CI, 0.516-0.586]), 0.549 [95% CI, 0.517-0.583], and 1.014 [95% CI, 0.907-1.135], for none vs. once, none vs. twice, none vs. once or twice, and once vs. twice for any influenza, respectively). Both one- and two-dose regimens significantly reduced cases with any influenza and influenza A every season. Also, both regimens significantly reduced cases of any influenza, influenza A, and influenza B among children aged 1-12 years, especially among those aged 1-5 years. In the 2013/14, 2015/16, and 2016/17 seasons, however, only the two-dose regimen was significantly effective in preventing influenza B. Both one- and two-dose regimens significantly reduced cases involving hospitalization due to any influenza and influenza A.
CONCLUSIONS:
Both one- and two-doses regimens of IIV were effective in preventing influenza for children aged 6 months to 12 years. The two-dose regimen was more effective against influenza B in some seasons.
Copyright ? 2019 Elsevier Ltd. All rights reserved.
KEYWORDS:
Children; Effectiveness; Hospitalization; Influenza vaccine; Test-negative case control; Vaccine dose
PMID: 31186191 DOI: 10.1016/j.vaccine.2019.05.090