在应用麻疹减毒活疫苗(以下简称麻疹疫苗)以前,麻疹的发病率和病死率均很高。麻疹疫苗研制成功并广泛应用十几年来,各地普遍的经验证明,免疫效果良好,能降低麻疹的发病率,控制流行,故显现出良好的流行病学效果。但是,在接种疫苗后的儿童中尚有发生麻疹者,其至某些地区出现局部暴发性流行。这些现象早已引起人们的关注,并且已成为当前麻疹流行病学研究的重要课題。 The measles morbidity and mortality rates were high before live attenuated measles vaccine (hereinafter referred to as measles vaccine). Measles vaccine developed successfully and widely used for more than a decade, the prevailing experience around the world that the immune effect is good, can reduce the incidence of measles, control of the epidemic, it shows a good epidemiological effect. However, there are still measles cases among vaccinated children, which have had a partial outbreak in some areas. These phenomena have long drawn people’s attention and have become an important issue in the current epidemiological study of measles.