JMIR Publications

ABSTRACT

Background:

The high prevalence of hepatitis A delivered a blow to public health decades ago. World Health Organization (WHO) set a goal on eliminating viral hepatitis including hepatitis A by 2030. In 2008, hepatitis A vaccines were integrated into the Expanded Program on Immunization (EPI) in China to alleviate the burden of hepatitis A, while the effectiveness of EPI has not been well investigated.

Objective:

We aimed to evaluate the intervention effect at both provincial and national levels on the incidence of hepatitis A in the Chinese mainland from 2005 to 2019.

Methods:

Based on the monthly reported number of hepatitis A cases during 2005–2019 in each of 31 provinces, we adopted generalized additive models with an interrupted time series design to estimate province-specific effects of EPI on the incidence of hepatitis A among the target population aged 2–9 years during 2005–2019. We then pooled province-specific effect estimates using random-effects meta-analysis. We also assessed the effect among the non-target and the whole population.

Results:

A total of 98,275 hepatitis A cases aged 2–9 years were reported in the Chinese mainland during 2005–2019, with an average annual incidence of 5.33 cases per 100,000 persons. Nationally, EPI decreased the hepatitis A incidence by 80.52% (excess risk (ER)= -80.77%, 95% confidence interval [CI]: -85.86%, -72.92%,) during the study period, guarding an annual average of 28.52 (95% empirical confidence interval [eCI]: 27.37, 29.00) cases per 100,000 persons among the target children against hepatitis A. Western China saw the more significant effect of EPI on the decrease of the hepatitis A incidence among target children. A greater number of the target children were protected from infection in northwest and southwest China, with an EIR of -129.72 (95% eCI: -135.67, -117.86) and -66.61 (95% eCI: -67.63, -64.22) cases per 100,000 persons on average, respectively. Intervention effects among non-target (ER = -32.88%, 95% CI: -39.76%, -25.21%) and whole populations (ER = -31.97%, 95% CI: -39.61%, -23.37%) were relatively small.

Conclusions:

The EPI has presented a lasting positive effect on the hepatitis A containment in the target population in China. The EPI on target children also provided a degree of indirect protection for unvaccinated individuals. The continuous surveillance of hepatitis A and the maintenance of mass vaccination would shore up the accomplishment in the decline of hepatitis A incidence to ultimately achieve the goal set by WHO.