6月龄婴儿麻疹疫苗免疫效果及人体反应观察

Immune Response and Clinical Reaction to Measles Vaccine in 6-month old Infants

疫苗时代育龄期妇女体内麻疹抗体多为麻疹疫苗所介导 ,所生婴儿母传抗体消失提前 ,未及初免月龄已成为易感者。针对北京市及其它一些大城市 <8月龄婴儿麻疹发病越来越突出的情况 ,为控制该人群发病 ,选取北京市户籍的 6月龄婴儿 119人进行麻疹减毒活疫苗 (MV)免疫效果及人体反应观察。结果显示 :6月龄婴儿中有 84%母传抗体已阴转 ,阳性者抗体水平也极低。接种MV后抗体阳性率达到 86 6 % ,免疫成功率为 80 7% ,几何平均滴度 (GMT)为 1∶5 2 8 45 ;接种后的发热率、皮疹率分别为 16 8%、2 5 2 %。提示实施 6月龄的MV初免程序是可行的。与本市 8月龄婴儿初免监测数据相比 ,6月龄婴儿的MV免疫成功率和GMT偏低 ,提示婴儿母传抗体的存在对MV的免疫成功率有一定的干扰作用外 ,与年龄相关的因素如低月龄婴儿免疫系统的发育程度可能是影响免疫效果的更为主要的因素。建议 :对 6月龄和 8月龄婴儿MV初免的成本效果进行研究 ,如果采取 6月龄初免 ,应考虑在满 1岁时复种 1剂MV ;加快研制免疫原性好并适用于低月龄婴儿的新型MV ;对与年龄有关的因素作更深入的探索。

In vaccine era, measles antibody in women of childbearing age is vaccine-induced, and the maternal antibody of their infants disappeared in advance. In big city, such as Beijing, more and more <8 month old infants who do not reach the first immunization age are attacked by measles virus. We selected 119?6 month old infants, giving them measles vaccine (MV) , to observe their immune response and clinical reaction. The results showed the maternal antibody in 84% of the 6 month old infants before vaccination were negative, and the antibody level in rest of them were very low. After MV vaccination, their seropositive rate reached 86.6%, the immunization successful rate was 80.7%, the GMT was 1∶528.45, the rates for fever and rash were 16.8% and 2.52% respectively, suggesting that the first vaccination of MV in 6 month old infants is feasible. Compared with infants primarily vaccinated at 8 months old, both the immunization successful rate and GMT were lower. This means that there is interference of residual maternal antibody with vaccine but most chiefly contributes to the immature development of the immune system of the infants (age related factor). We recommend to give the first dose of MV to infants of 6 months old and the second dose at 1 year old, but before doing this, it is necessary to do cost effectiveness analysis and to explore new MV with good antigenicity to infants of lower age.