A discrete-time model with vaccination for a measles epidemic.

A discrete-time, age-independent SIR-type epidemic model is formulated and analyzed. The effects of vaccination are also included in the model. Three mathematically important properties are verified for the model: solutions are nonnegative, the population size is time-invariant, and the epidemic concludes with all individuals either remaining susceptible or becoming immune (a property typical of SIR models). The model is applied to a measles epidemic on a university campus. The simulated results are in good agreement with the actual data if it is assumed that the population mixes nonhomogeneously. The results of the simulations indicate that a rate of immunity greater than 98% may be required to prevent an epidemic in a university population. The model has applications to other contagious diseases of SIR type. Furthermore, the simulated results of the model can easily be compared to data, and the effects of a vaccination program can be examined.     

Live measles vaccine: a 21 year follow up.

21 years after receiving Schwartz strain live measles vaccine 4500 trial participants showed a continuing high level of protection compared with those who were unvaccinated. Over the last seven years of the follow up no cases of measles were reported in vaccinated participants who had had close contact with the disease. Immunity induced by the vaccine seems to survive the challenge of close contact with measles in young children, even after 21 years.     

许昌市2010年麻疹疫情分析

研究许昌市麻疹流行特征,为消除麻疹提供科学依据.对许昌市2010年麻疹疫情进行描述流行病学分析.结果显示2010年全市共报告麻疹确诊病例158例,报告发病率为3.74/10万;流行毒株为麻疹病毒H1a基因型.3-5月份是发病高峰;0～3岁龄儿童为主,其中小于8月龄病例占报告发病数的32.91％;8- 17月龄病例,68...     

Encephalitis after administration of live measles vaccine.

In a previously well child with no evidence of pre-existing immunologic defect a fatal encephalitis developed 10 days after administration of measles vaccine. There was pathologic evidence of an early viral encephalitis characterized by perivascular mononulcear infiltrates. Although the virus was not recovered, the diagnosis of a measles virus infection and encephalitis is supported by the postmortem findings of Warthin-Finkeldey cells in lymphoid tissues, an intranuclear inclusion in the brain and histologic changes of encephalitis.     

杭州地区婴儿麻疹流行特征与疫苗接种史的相关性分析

本文旨在探讨当前我国麻疹疫苗接种程序下的婴儿麻疹流行特征,为改进麻疹疫苗接种策略提供科学依据。利用麻疹监测系统,对杭州市2004～2007年婴儿麻疹发病的分布和疫苗免疫状况进行分析,发现婴儿麻疹发病率无明显城乡差异,发病季节主要集中在3～5月,发病年龄主要集中在5～9月龄。≤8月龄病例以常住儿童为主,≥9月龄病例以流动儿童为主。≥9月龄麻疹病例中,常住儿童所占比例低于流动儿童,而其麻疹疫苗接种率(47.5%)明显高于流动儿童(14.3%),两者有显著差异(χ2=11.75,P0.01)。因此,为进一步降低婴儿麻疹发病率,需加强流动儿童的麻疹疫苗补种;另外,建议将麻疹疫苗初次免疫时间提前至6月龄,这可能有助于降低婴儿麻疹发病率。     

Successful boosting of a DNA measles immunization with an oral plant-derived measles virus vaccine

Despite eradication attempts, measles remains a global health concern. Here we report results that demonstrate that a single-dose DNA immunization followed by multiple boosters, delivered orally as a plant-derived vaccine, can induce significantly greater quantities of measles virus-neutralizing antibodies than immunization with either DNA or plant-derived vaccines alone. This represents the first demonstration of an enhanced immune response to a prime-boost vaccination strategy combining a DNA vaccine with edible plant technology.