Plos One:流感疫苗对孩子有预防效果吗

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小孩接种流感疫苗到底有没有预防效果？日本研究人员最新调查发现，不同年龄段的孩子，接种疫苗后，预防流感的效果是不同的。例如，６个月至１１个月年龄段的孩子和１３岁至１５岁年龄段的孩子即使接种了流感疫苗，也没有预防效果。

日本庆应义塾大学的研究人员以４７００多名孩子为调查对象，这些孩子年龄从６个月至１５岁不等，都出现过３８摄氏度以上的发热，并于２０１３年１１月至２０１４年３月到该校附属２２家医院就诊。

研究小组调查了这些孩子是否感染流感病毒以及是否接种过流感疫苗，并且分析了各种流感疫苗对于预防甲型和乙型等流感的效果。如果接种了疫苗，但是仍有很多感染病例，则预防效果很低；如果接种疫苗后很少有人感染，则预防效果就高。

结果显示，６个月至１１个月年龄段的婴儿在接种疫苗后，并不能预防甲型流感。而１３岁至１５岁年龄段的中学生接种疫苗后，既不能预防甲型流感，也不能预防乙型流感。

不过，在其他年龄段，流感疫苗对甲型流感的预防效果较好。研究小组认为，在１岁至１２岁阶段，流感疫苗能够预防６０％至７０％的发病，特别是对甲型Ｈ１Ｎ１流感的预防效果更好。

人们一直希望接种疫苗后能够预防流感发展成重症。研究小组通过对全部年龄段进行调查后发现，甲型流感疫苗整体上可以减少７６％的重症化，甲型Ｈ１Ｎ１流感疫苗可以减少９０％的重症化。不过乙型流感疫苗则没有发现有预防重症化的效果，而且此次调查还显示不分年龄段整体上乙型流感疫苗的有效率只有２６％。

研究小组对２０１４年至２０１５年的相关数据进行分析，也得出了同样的结果。相关论文发表在新一期美国《科学公共图书馆综合》杂志网络版上。

来源：新华网

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Effectiveness of Trivalent Inactivated Influenza Vaccine in Children Estimated by a Test-Negative Case-Control Design Study Based on Influenza Rapid Diagnostic Test Results

Masayoshi Shinjoh , Norio Sugaya  , Yoshio Yamaguchi , Yuka Tomidokoro , Shinichiro Sekiguchi , Keiko Mitamura , Motoko Fujino , Hiroyuki Shiro , Osamu Komiyama , Nobuhiko Taguchi , Yuji Nakata , Naoko Yoshida , Atsushi Narabayashi , Michiko Myokai , Masanori Sato , Munehiro Furuichi , Hiroaki Baba , Hisayo Fujita , Akihiro Sato , Ichiro Ookawara , Kenichiro Tsunematsu , Makoto Yoshida , Mio Kono , Fumie Tanaka , Chiharu Kawakami, Takahisa Kimiya, Takao Takahashi, Satoshi Iwata,

Abstract

We assessed vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza in children 6 months to 15 years of age in 22 hospitals in Japan during the 2013–14 season. Our study was conducted according to a test-negative case-control design based on influenza rapid diagnostic test (IRDT) results. Outpatients who came to our clinics with a fever of 38°C or over and had undergone an IRDT were enrolled in this study. Patients with positive IRDT results were recorded as cases, and patients with negative results were recorded as controls. Between November 2013 and March 2014, a total of 4727 pediatric patients (6 months to 15 years of age) were enrolled: 876 were positive for influenza A, 66 for A(H1N1)pdm09 and in the other 810 the subtype was unknown; 1405 were positive for influenza B; and 2445 were negative for influenza. Overall VE was 46% (95% confidence interval [CI], 39–52). Adjusted VE against influenza A, influenza A(H1N1)pdm09, and influenza B was 63% (95% CI, 56–69), 77% (95% CI, 59–87), and 26% (95% CI, 14–36), respectively. Influenza vaccine was not effective against either influenza A or influenza B in infants 6 to 11 months of age. Two doses of influenza vaccine provided better protection against influenza A infection than a single dose did. VE against hospitalization influenza A infection was 76%. Influenza vaccine was effective against influenza A, especially against influenza A(H1N1)pdm09, but was much less effective against influenza B.

http://journals.plos.org/plosone ... ournal.pone.0136539