Effectiveness assessment of of vaccination policy against measles epidemic in Japanusing an age-time two-dimensional mathematical model.
Effectiveness assessment of of vaccination policy against measles epidemic in Japanusing an age-time two-dimensional mathematical model.
复制标题
使用年龄-时间二维数学模型评估日本麻疹疫情疫苗接种政策的有效性。
DOI：
10.1007/s12199-011-0217-y
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Ishikawa H
中科院分区：
文献类型：
--
作者：
Maitani Y;Ishikawa H
目的2007年，麻疹在日本青少年和青壮年人群中流行，造成了一个严重的社会问题。在发达国家中，日本是麻疹发病率较高的国家。本研究的目的是通过模拟评估麻疹疫苗接种政策改进的效果。方法我们建立了麻疹传播的年龄-时间二维模型，反映了年龄结构，使接触率能够按年龄选择。在模型中引入母体免疫类别，可以在婴儿母亲获得免疫的过程中区分自然感染和疫苗接种，从而提高婴儿模拟的准确性。结果本次定量研究的结果表明，控制麻疹暴发需要保持较高的疫苗接种率，疫苗接种率下降可能导致麻疹流行。结论目前的麻疹标准免疫方案将维持可接受的免疫水平，因此，在第三和第四阶段如期停止接种后，疫情风险较低--只要保持第一和第二阶段至少90%的疫苗接种率。模拟结果表明，如期停止第三和第四阶段疫苗接种的同时，应努力保持第一和第二阶段的适当高疫苗覆盖率。
ObjectivesIn 2007, measles prevailed among the youth and young adult population in Japan, creating in a serious social problem. Among the developed countries, Japan has a relatively high incidence of measles. The objective of this study was to assess the effect of improvements in the vaccination policy against measles through simulations.MethodsWe developed an age–time two-dimensional model for the transmission of measles to reflect an age structure, enabling contact rate to be selected by age. Introduction of the maternal immunity class into the model allowed natural infection and vaccination to be discriminated along the course of an infant’s mother acquiring the immunity, thereby resulting in an improved accuracy of the simulations in infants. Several vaccination scenarios were attempted in order to assess the influence of various vaccination policies on the prevention of a measles epidemic.ResultsThe results of this quantitative study indicated that suppression of a measles outbreak requires the maintenance of high vaccine coverage and that a decline in vaccine coverage may result in a measles epidemic.ConclusionsThe present standard immunization program for measles will maintain an acceptable level of immunity and is therefore associated with a low risk of an epidemic after discontinuation of the third and fourth stages as scheduled—as long as at least 90% vaccine coverage of the first and second is maintained. The simulation results show that discontinuation of the third and fourth stages of vaccination as scheduled should be accompanied by endeavors to maintain appropriate high vaccine coverage of the first and second stages.