Analysis of historical data suggests long-lasting protective effects of smallpox vaccination
Analysis of historical data suggests long-lasting protective effects of smallpox vaccination
复制标题
DOI：
10.1093/aje/kwg225
复制
发表时间：
2003-10-15
影响因子：
5
通讯作者：
Eichner, M
中科院分区：
文献类型：
--
作者：
Eichner, M
超过一半的美国人口已经接种了天花疫苗，但目前还不清楚有多少人仍然受到感染和疾病的保护。因此，在当前的生物恐怖主义辩论中，剩余保护和与年龄相关的病死率被广泛忽视。作者分析了1902-1903年来自英国利物浦的数据，以及1950-1971年该疾病重新引入欧洲的数据，以估计接种疫苗的病例在多大程度上免受严重或致命疾病的影响，以及这种保护随着时间的推移减弱的速度。对严重和致命性疾病的保护以每年1.41%的速度丧失，对应于49.2年的半衰期（95%置信区间：42.0，57.3），仅对致命性疾病的保护每年下降0.363%。因此，即使在初次接种后70年，77.6%的病例仍然受到保护（95%置信区间：66.6，85.4）。因此，在接种一次疫苗后，对严重疾病的保护应该延长几十年，对大多数接种者来说，对天花死亡的保护甚至可能是终身的。这种保护应该大大减少生物恐怖袭击中预期的严重和致命病例的数量，但残留保护也可能增加一些以前接种疫苗的病例在自由移动和传播感染的同时，可能会更长时间地不被识别的风险。
More than half of the US population has received the smallpox vaccine, but it is unknown what fraction is still protected against infection and disease. Residual protection and age-dependent case-fatality ratios have therefore been widely neglected in the current bioterrorism debate. The author analyzed 1902-1903 data from Liverpool, United Kingdom, and from reintroductions of the disease to Europe in 1950-1971 to estimate to what degree vaccinated cases were protected against developing severe or fatal disease and how quickly this protection waned over time. Protection against severe and fatal disease was lost at the rate of 1.41% per year, corresponding to a half-life of 49.2 years (95% confidence interval: 42.0, 57.3), and protection against fatal disease alone declined 0.363% per year. Thus, even 70 years after primary vaccination, 77.6% of cases were still protected (95% confidence interval: 66.6, 85.4). Protection against severe disease should therefore extend for many decades after a single vaccination, and protection against death from smallpox may even be lifelong for the majority of vaccinees. This protection should greatly reduce the number of severe and fatal cases of disease expected in a bioterrorist attack, but residual protection may also increase the risk that some previously vaccinated cases who develop mild disease may remain unrecognized longer, while moving around freely and disseminating the infection.