Epidemiology and Surveillance Unit, Centre for Infectious Disease Control, National institute for Public Health and the Environment, Bilthoven, The Netherlands.
BMC Infect Dis. 2011 Jul 18;11:196. doi: 10.1186/1471-2334-11-196.
During the 2009 influenza A/H1N1 pandemic, adjuvanted influenza vaccines were used for the first time on a large scale. Results on the effectiveness of the vaccines in preventing 2009 influenza A/H1N1-related hospitalisation are scanty and varying.
We conducted a matched case-control study in individuals with an indication for vaccination due to underlying medical conditions and/or age ≥ 60 years in The Netherlands. Cases were patients hospitalised with laboratory-confirmed 2009 A/H1N1 influenza infection between November 16, 2009 and January 15, 2010. Controls were matched to cases on age, sex and type of underlying medical condition(s) and drawn from an extensive general practitioner network. Conditional logistic regression was used to estimate the vaccine effectiveness (VE = 1 - OR). Different sensitivity analyses were used to assess confounding by severity of underlying medical condition(s) and the effect of different assumptions for missing dates of vaccination.
149 cases and 28,238 matched controls were included. It was estimated that 22% of the cases and 28% of the controls received vaccination more than 7 days before the date of onset of symptoms in cases. A significant number of breakthrough infections were observed. The VE was estimated at 19% (95%CI -28-49). After restricting the analysis to cases with controls suffering from severe underlying medical conditions, the VE was 49% (95% CI 16-69).
The number of breakthrough infections, resulting in modest VE estimates, suggests that the MF-59™ adjuvanted vaccine may have had only a limited impact on preventing 2009 influenza A/H1N1-related hospitalisation in this setting. As the main aim of influenza vaccination programmes is to reduce severe influenza-related morbidity and mortality from influenza in persons at high risk of complications, a more effective vaccine, or additional preventive measures, are needed.
在 2009 年甲型 H1N1 流感大流行期间，首次大规模使用了佐剂流感疫苗。关于疫苗在预防 2009 年甲型 H1N1 流感相关住院方面的有效性的结果很少且各不相同。
我们在荷兰对因基础医学状况和/或年龄≥60 岁而有接种疫苗指征的个体进行了一项匹配病例对照研究。病例为 2009 年 11 月 16 日至 2010 年 1 月 15 日期间因实验室确诊的 2009 年 A/H1N1 流感感染而住院的患者。对照组与病例按年龄、性别和基础医学状况类型相匹配，并从广泛的全科医生网络中抽取。使用条件逻辑回归估计疫苗效力（VE=1-OR）。使用不同的敏感性分析来评估基础医学状况严重程度混杂的影响，以及不同假设的疫苗接种缺失日期的影响。
共纳入 149 例病例和 28238 例匹配对照。据估计，22%的病例和 28%的对照在病例发病日期前超过 7 天接种了疫苗。观察到大量突破感染。估计 VE 为 19%（95%CI-28-49）。在将分析限制为患有严重基础医学状况的对照病例后，VE 为 49%（95%CI 16-69）。
突破感染的数量导致适度的 VE 估计表明，MF-59™佐剂疫苗在这种情况下可能对预防 2009 年甲型 H1N1 流感相关住院的影响有限。由于流感疫苗接种计划的主要目的是减少高危人群中因流感引起的严重流感相关发病率和死亡率，因此需要更有效的疫苗或其他预防措施。
