Zhuang F, Jiang Q, Gong Y
Institute of Viral Diseases, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2001 Jun;22(3):188-90.
To assess the long-term epidemiological effects after a mass vaccination program, using live attenuated hepatitis A vaccine (H(2)-strain).
Shengsi county and Jiaojiang city in Zhejiang province were chosen where high incidence rate of hepatitis A was observed. Mass vaccination program of H(2)-strain vaccine was carried out on 1 - 15 year olds. Cohort studies included two groups were carried out in Shengsi. Cases reported program on hepatitis A was under the national standard on clinical diagnosis and partly through laboratory monitor of anti-HAV IgM and IgG, ELISA and Abbott EIA. Population size was estimated by the yearly reports of census bureau of the county and the city. Serum tests including neutralization test, immune-recall responses, and anti-HAV IgG were performed 10 years after the initial immunization.
The morbidity of hepatitis A was significantly different between vaccinated groups and non-vaccinated groups (P < 0.01) in the cohort study. The protective efficacy in the site was 100 percent. There was a significantly negative correlation of regression between vaccine coverage and hepatitis A morbidity. In both sites, hepatitis A incidence rate showed decrease of 94.5% and 90.3% in whole population, with 96.9% and 97.9% in 1 - 15 year olds respectively. Neutralization test showed that 63.8% of the serum negative to ELISA after vaccination could still neutralize certain HAV. Immune-recall response after the booster was seen in vaccine group with 80.2% positive rate of anti HAV-IgG, 10 years after immunization among vaccinees in both sites. Not a single hepatitis A case was identified.
Live attenuated hepatitis A vaccine seemed to have obviously long-term epidemiological effects.
评估使用甲型肝炎减毒活疫苗（H2株）大规模接种计划后的长期流行病学效果。
选择浙江省发病率较高的嵊泗县和椒江市。对1至15岁人群开展H2株疫苗大规模接种计划。在嵊泗县进行了两组队列研究。甲型肝炎病例报告程序符合国家标准临床诊断，部分通过抗-HAV IgM和IgG的实验室监测、酶联免疫吸附测定（ELISA）和雅培酶免疫测定（EIA）。人口规模根据县和市统计局的年度报告估算。初次免疫10年后进行血清检测，包括中和试验、免疫回忆反应和抗-HAV IgG检测。
队列研究中，接种组和未接种组的甲型肝炎发病率存在显著差异（P<0.01）。当地的保护效力为100%。疫苗接种率与甲型肝炎发病率之间存在显著的负回归相关性。在两个地区，全人群甲型肝炎发病率分别下降了94.5%和90.3%，1至15岁人群分别下降了96.9%和97.9%。中和试验表明，接种后ELISA检测为阴性的血清中，63.8%仍能中和一定量的甲型肝炎病毒。在两个地区的疫苗接种者中，初次免疫10年后进行加强免疫，疫苗组出现免疫回忆反应，抗HAV-IgG阳性率为80.2%。未发现一例甲型肝炎病例。
甲型肝炎减毒活疫苗似乎具有明显的长期流行病学效果。
