这项研究的目的是评估流感疫苗的有效性(VE)2016/17流行的甲型H1N1和甲型(H3N2)病毒在北京,中国的首都。
这项以监测为基础的研究通过流感病毒监测纳入了所有擦拭过的患者,2016年11月至2017年4月。在门诊环境中,使用测试阴性病例对照设计来评估流感VE与医疗护理实验室确认的流感。病例为流感样疾病(ILI)患者,他们的流感检测呈阳性,对照组为流感阴性患者。
共纳入10,496例ILI患者并进行擦拭。其中,735甲型(H1N1)pdm09检测呈阳性,1851甲型(H3N2)检测呈阳性,在1851种甲型(H3N2)流感病毒中随机选择的45种标本中,B型为40种,2(4.4%)属于H3N23C.2a1进化枝,43人(95.6%)属于A/HongKong/4801/2014-like3C.2a进化枝。在3C.2a进化枝的43种病毒中,32种病毒聚集在一个携带T131K的亚组中,R142K和R261Q取代。针对所有流感的调整后VE均低至25%(95%置信区间(CI):0-43%),甲型流感(H1N1)pdm09占54%(95CI:22-73%),甲型流感(H3N2)占2%(95CI:-35%至29%)。
我们的研究表明,在北京,甲型H1N1流感pdm09的VE适中,但甲型流感(H3N2)的VE较低,2016/17赛季。血凝素中的氨基酸取代可能导致本季针对甲型流感(H3N2)的低VE。
The objective of this study was to estimate influenza vaccine effectiveness (VE) for the 2016/17 epidemic of co-circulating influenza A(H1N1)pdm09 and A(H3N2) viruses in Beijing, the capital of China.
The surveillance-based study included all swabbed patients through influenza virological surveillance, between November 2016 and April 2017. A test-negative
case-control design was used to estimate influenza VE against medically-attended laboratory-confirmed influenza in outpatient settings. Cases were influenza-like illness (ILI) patients who tested positive for influenza, and controls were influenza negative patients.
A total of 10,496 ILI patients were enrolled and swabbed. Among them, 735 tested positive for influenza A(H1N1)pdm09, 1851 for A(H3N2), and 40 for type B. Of the 45 randomly selected specimens out of 1851 influenza A(H3N2) viruses, 2(4.4%) belonged to the H3N2 3C.2a1 clade, and 43(95.6%) belonged to A/Hong Kong/4801/2014-like 3C.2a clade. Among the 43 viruses of the 3C.2a clade, 32 viruses clustered in one subgroup carrying T131K, R142K and R261Q substitutions. The adjusted VE against all influenza was low at 25% (95% confidence interval (CI): 0-43%), with 54% (95%CI: 22-73%) for influenza A(H1N1)pdm09, and 2% (95%CI: -35% to 29%) for influenza A(H3N2).
Our study suggested a moderate VE against influenza A(H1N1)pdm09, but low VE against influenza A(H3N2) in Beijing, 2016/17 season. Amino acid substitutions in the hemagglutinin may contribute to the low VE against influenza A(H3N2) for this season.