Zhuang Gui-Hua, Pan Xin-Juan, Wang Xue-Liang
Department of Epidemiology and Biostatistics, School of Medicine, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China.
Vaccine. 2008 Aug 18;26(35):4608-16. doi: 10.1016/j.vaccine.2008.05.086. Epub 2008 Jun 13.
The socioeconomic improvement has impacted hepatitis A virus (HAV) infection with a shift from high to intermediate endemicity in many parts of China. The first China-developed inactivated hepatitis A vaccine, with significantly low price, was licensed in 2002, prompting us to evaluate whether universal childhood vaccination is advisable now in China. We considered vaccination scheduled at ages 12 and 18 months for all healthy children, and assumed that a single cohort was enrolled in 2005. A Markov model was used to predict hepatitis A outcomes and costs. Vaccination was compared with no vaccination, and the cost-effectiveness of vaccination was evaluated from the health system and the societal perspectives. The analysis was run separately in five regions (covering all the 31 provinces of Mainland China) defined by anti-HAV prevalence (around 50%, 50-69%, 70-79%, 80-89% and 90%-). The study projects that with the Chinese low-cost vaccine, vaccination could gain quality adjusted life years (QALYs) through the whole country and save health system or societal costs in the lowest, lower, intermediate and higher infection regions. Vaccination should also be cost-effective in the highest infection region because of low additional costs per QALY gained. However, vaccination would increase the probability of death due to hepatitis A in the highest and higher infection regions by 38 and 37 per million enrolled, respectively, and as vaccine protection loss increases the risk would also occur in intermediate and lower infection regions. The trend that the lower infection level the region has, the more cost-effective vaccination would be is obvious. Sensitivity analyses prove that our conclusions are robust. Considering the potential risk of vaccination, as well as unbalanced socioeconomic developments and significant differences in HAV infection through the whole country, the study suggests that universal childhood hepatitis A vaccination should be first administrated in provinces with the lowest infection level. With knowledge accumulation and further evaluations, the zone of immunization would be considered to be expanded gradually from provinces with lower infection level to those with higher.
社会经济的改善已对甲型肝炎病毒(HAV)感染产生影响,在中国许多地区,其流行程度已从高度流行转变为中度流行。2002年,中国自主研发的首批甲型肝炎灭活疫苗获批上市,价格显著低廉,这促使我们评估目前在中国对儿童进行普遍接种疫苗是否可取。我们考虑为所有健康儿童在12个月和18个月时安排接种疫苗,并假设在2005年纳入了一个单一队列。采用马尔可夫模型预测甲型肝炎的结局和成本。将接种疫苗与不接种疫苗进行比较,并从卫生系统和社会角度评估接种疫苗的成本效益。根据抗-HAV流行率(约50%、50 - 69%、70 - 79%、80 - 89%和90%及以上)将中国大陆31个省份划分为五个区域,分别进行分析。该研究预测,使用中国的低成本疫苗,在全国范围内接种疫苗可获得质量调整生命年(QALY),并在感染率最低、较低、中等和较高的地区节省卫生系统或社会成本。在感染率最高的地区,由于每获得一个QALY的额外成本较低,接种疫苗也应具有成本效益。然而,在感染率最高和较高的地区,接种疫苗将分别使每百万纳入者中因甲型肝炎死亡的概率增加38和37,并且随着疫苗保护作用的丧失,在感染率中等和较低的地区也会出现这种风险。地区感染水平越低,接种疫苗的成本效益越高,这一趋势很明显。敏感性分析证明我们的结论是可靠的。考虑到接种疫苗的潜在风险,以及全国社会经济发展不平衡和甲型肝炎感染存在显著差异,该研究建议应首先在感染率最低的省份对儿童进行普遍的甲型肝炎疫苗接种。随着知识的积累和进一步评估,免疫接种范围将考虑逐步从感染率较低的省份扩大到感染率较高的省份。