随访检测麻疹流行后疫苗再免前后麻疹IgG抗体水平

The surveillance of the level of measles IgG antibody of children during measles outbreak and before and after revaccination

目的探讨高度免疫人群中麻疹流行的原因，了解麻疹再免前后麻疹ＩｇＧ抗体水平变化的规律。方法在麻疹流行时群体抽样，用酶联免疫吸附实验检验麻疹ＩｇＧ抗体，并在麻疹流行后９个月及再免后６周行随访检测。结果麻疹流行时７０．４％（１０７／１５２）的患儿ＩｇＧ抗体滴度≤１：２００。流行后再免前仍有４１．７％（６０／１４４）滴度≤１：２００。再免后６周抗体水平明显升高，抗体滴度为１：２００者仅为９．２％（１２／１３０）。结论麻疹流行前３个月强化免疫失败，造成麻疹流行；流行后再免成功。

Objective To study why the outbreak of measles still occurs in a highly vaccinated population and to understand the profile of measles virus specific IgG antibody before and after revaccination. Methods During measles outbreak serum samples were collected by cluster sampling from primary school of the oil field base of Zungur East of Xinjiang. Nine months after the outbreak, and before and 6 weeks after the revaccination, the serum samples were collected. Measles virus specific IgG antibody was tested by the enzyme linked immunosorbent assay (ELISA). Results During measles outbreak the titer of measles IgG antibody ≤1:200 was seen in 70.4% (107/152) of the population tested, and 41.7% (60/144) 9 months later. It was only 9.2% (12/130) after 6 weeks of revaccination. Geometric mean titer (GMT) of measles IgG antibody was higher 6 weeks after revaccination than that before vaccination ( u =5.34, P <0.01). Conclusion Failure of booster dose inoculation of measles vaccine 3 months before measles outbreak among. Pupils of oil field base school was the reason of the measles outbreak, but revaccination 9 months after measles outbreak was successful.