Victorian Infectious Diseases Reference Laboratory 10 Wreckyn Street, North Melbourne, Victoria 3051, Australia.
BMC Infect Dis. 2011 Jun 14;11:170. doi: 10.1186/1471-2334-11-170.
Antigenic variation of influenza virus necessitates annual reformulation of seasonal influenza vaccines, which contain two type A strains (H1N1 and H3N2) and one type B strain. We used a test negative case control design to estimate influenza vaccine effectiveness (VE) against influenza by type and subtype over two consecutive seasons in Victoria, Australia.
Patients presenting with influenza-like illness to general practitioners (GPs) in a sentinel surveillance network during 2007 and 2008 were tested for influenza. Cases tested positive for influenza by polymerase chain reaction and controls tested negative for influenza. Vaccination status was recorded by sentinel GPs. Vaccine effectiveness was calculated as [(1--adjusted odds ratio) × 100%].
There were 386 eligible study participants in 2007 of whom 50% were influenza positive and 19% were vaccinated. In 2008 there were 330 eligible study participants of whom 32% were influenza positive and 17% were vaccinated. Adjusted VE against A/H3N2 influenza in 2007 was 68% (95% CI, 32 to 85%) but VE against A/H1N1 (27%; 95% CI, -92 to 72%) and B (84%; 95% CI, -2 to 98%) were not statistically significant. In 2008, the adjusted VE estimate was positive against type B influenza (49%) but negative for A/H1N1 (-88%) and A/H3N2 (-66%); none was statistically significant.
Type- and subtype-specific assessment of influenza VE is needed to identify variations that cannot be differentiated from a measure of VE against all influenza. Type- and subtype-specific influenza VE estimates in Victoria in 2007 and 2008 were generally consistent with strain circulation data.
流感病毒的抗原变异使得每年都需要对季节性流感疫苗进行重新配方，其中包含两种 A 型株（H1N1 和 H3N2）和一种 B 型株。我们使用了一个病例对照研究设计，在澳大利亚维多利亚州连续两个季节估计流感疫苗对流感的效果（VE）。
在一个哨点监测网络中，向全科医生（GP）就诊的具有流感样症状的患者接受了流感检测。聚合酶链反应检测呈流感阳性的病例和检测呈流感阴性的对照。哨点 GP 记录了疫苗接种情况。疫苗效果的计算方法为[（1-调整后的优势比）×100%]。
2007 年有 386 名符合条件的研究参与者，其中 50%为流感阳性，19%为接种疫苗者。2008 年有 330 名符合条件的研究参与者，其中 32%为流感阳性，17%为接种疫苗者。2007 年，针对 A/H3N2 流感的调整后 VE 为 68%（95%CI，32%至 85%），但针对 A/H1N1（27%；95%CI，-92%至 72%）和 B（84%；95%CI，-2%至 98%）的 VE 无统计学意义。2008 年，针对 B 型流感的调整后 VE 估计值为阳性（49%），但针对 A/H1N1（-88%）和 A/H3N2（-66%）的 VE 为阴性；均无统计学意义。
需要对流感 VE 的型别和亚型特异性进行评估，以确定不能通过对所有流感的 VE 进行测量来区分的变异。2007 年和 2008 年在维多利亚州的流感 VE 型别和亚型特异性估计值与流行株循环数据基本一致。
