[目的]分析陕西省近年麻疹流行的疫苗免疫因素,研究现行麻疹疫苗对流行株的实际保护效果。[方法]用微量中和试验测定麻疹疫苗免疫血清和麻疹病人急性期血清对麻疹疫苗株和野毒株的中和抗体水平。[结果]健康儿童麻疹疫苗免疫血清和有免疫史的麻疹病人急性期血清对麻疹野毒株的中和抗体几何平均滴度(GMT)分别为61.04、30.24,明显低于对S191株的GMT105.61、83.72),S191株中和抗体效价≤8的健康儿童疫苗免疫血清中,有16.7%野毒株中和抗体阴性。[结论]由于麻疹流行株的抗原变异导致现行麻疹疫苗的保护力可能有所下降。 [Objective] To analyze the immunization factors of measles epidemic in Shaanxi Province in recent years and study the actual protective effect of the current measles vaccine on epidemic strains. [Method] The neutralizing antibody level of measles vaccine and wild virus in measles vaccine immune serum and measles patients acute phase serum was determined by micro neutralization test. [Results] The geometric mean titers (GMTs) of the neutralizing antibodies to the measles measles patients in measles patients with immune measles were 61.04 and 30.24, respectively, which were significantly lower than those of GMT105 against S191 strains. 61, 83.72), 16.7% of wild-type neutralizing antibodies were negative in the healthy children’s vaccine serum with S191 neutralizing antibody titer ≤8. [Conclusion] The protective capacity of the current measles vaccine may be decreased due to the antigenic variation of the measles epidemic strains.