RESUMO
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.
