甲肝免疫策略长期效果预测研究

目的结合我国现阶段的甲型肝炎免疫水平和流行情况,建立甲型肝炎传播动力学模型,预测对18月龄儿童接种甲肝减毒活疫苗以及对未接种的2～18岁儿童补种的甲肝免疫策略的长期效果。方法在Berkeley-Madonna软件中构建甲型肝炎的传播动力学模型(S-E-I-R-V),根据文献资料确定甲肝传播动力学模型参数;通过敏感性分析评价参数变化时模型预测结果的稳定性。结果不接种疫苗时,从2010年至2030年,预测甲肝累计发病人数将达到780×104,发病率为38.8/105;对18月龄儿童接种疫苗及2～18岁未接种儿童补种,在疫苗覆盖率达到38%～57%的情况下,至2030年甲肝累计发病人数为436×104～475×104,发病率为17.5/105～19.4/105。与不接种相比,发病人数将减少306×104～345×104,发病率下降幅度接近54%。敏感性分析提示,甲肝疫苗接种率高低对甲肝发病率影响明显,接种率为38%时,2030年甲肝发病率为19.4/105,接种率为90%时,2030年肝发病率为16.0/105。结论实施甲型肝炎的疫苗免疫接种,能够有效预防和控制甲型肝炎的流行。

Long term effectiveness of vaccination of Hepatitis A

Objective To develop a dynamic model of Hepatitis A transmission in order to predict the long-term effectiveness of Hepatitis A vaccination on 18 months old infants and 2 to 18 years old children.Methods A dynamic model of HA(S-E-I-R-V)was developed using the software Berkeley-Madonna.The parameters required for the model derived from literature.A sensitivity analysis was performed to assess the stability of the model through changing parameters.Results During the period of 2010 to 2030,the cumulative cases of Hepatitis A would reach 7.8 million with an incidence of 38.8 per 100,000 without vaccination.With 38% to 57% coverage of vaccination in children of 1.5-18 years old,the cumulative cases would decrease to 4.36-4.75 million with an incidence of 17.5-19.4 per 100,000.The vaccination was predicted to reduce 3.06-3.45 million Hepatitis A cases with an incidence reduction of 19.4-21.3 per 100,000.This suggests that Hepatitis A vaccination would achieve a 54% decrease in incidence of Hepatitis A.The sensitivity analysis showed that the coverage of vaccination had a significant impact on the incidence of Hepatitis A.By 2030,the incidence of Hepatitis A would decrease from 19.4 per 100,000 to 16.0 per 100,000 when the vaccination coverage increases from 38% to 90%.Conclusion Hepatitis A vaccination can effectively prevent and control the incidence of Hepatitis A.