甲型H1N1流感疫苗接种2年后免疫持久性评价

Immunity Durability of Influenza A (H1N1) Vaccine 2 Years After Vaccination

目的评价成都市甲型H1N1流感（甲流）疫苗接种2年后疫苗免疫持久性。方法以2011年接种甲型H1N1流感疫苗1年后HI抗体≥1：40的170人作为观察对象，用微量血凝抑制试验方法测定抗体，计算人群GMT和疫苗保护率。结果甲型H1N1流感疫苗免疫后2年观察对象GMT为1：32．60，较免疫后1年下降72．34％，保护率达70．O％，老年组保护率仅为48．49％。观察对象中免疫后2年有7．06％的人抗体滴度上升。经估算人群2年后保护率为49．23％；而3—11岁组、12～17岁组、18—59岁组、I〉60岁组估算保护率分别为46．96％、69．38％、45．63％和12．58％。结论甲流疫苗免疫后2年抗体大幅降低，人群失去保护屏障，具有保护性抗体的人数大幅减少，特别是老年组基本不具有甲流保护抗体，所有人群需再次接种。

Objective To evaluate the immunity durability of influenza A （ HIN1 ） 2 years after vaccination in Chengdu. Methods Totally 170 people with HI antibodies no less than 1 ： 40 one year after immunization were selected for observation and micro - hemagglutination inhibition test was adopted to determine the antibodies, and to calculate the GMT and the protection rate. Results Two years after vaccination, the GMT was 1 ： 32. 60 with a declination of 72. 34% compare with one year ago ; the overall protection rate was 70. 0% and for the elderly group, the protection rate was 48.49%. The antibody titer decreased in 7.06% of the subjects two years after the vaccination. The estimated protection rate were 49.23% two years after the vaccination. The estimated protective rates for 3 - 11 age group, 12 - 17 age group, 18 -59 age group and no less than 60 years group were respectively 46. 96%, 69.38%, 45.63% and 12. 58%. Conclusion Two years after the influenza A （H1N1） vaccination, the antibody titers are greatly reduced and thus those with protective antibodies sharply reduced, especially in elderly group, indicating a necessity of revaccinated.