To explore epidemiological changes of Japanese encephalitis (JE) in a long-time span and evaluate the impact of mass immunisation. Data on JE cases from hospitals and the county Centers for Disease Control and Prevention in Guizhou Province was collected between 2005 and 2021. Epidemiological changes were analyzed according to a series of policy implementations and the coronavirus disease 2019 (COVID-19) pandemic. A total of 5138 JE cases and 152 deaths were reported in Guizhou Province during 2005–2021. The average incidence and case fatality rates were 0.83/100,000 and 2.96%, respectively. The JE prevalence showed a declining trend over the years with the reduced incidence gap between age groups and narrowing of the high-epidemic regions. During the COVID-19 pandemic, the JE activity reached its nadir in 2020. The inclusion in the Expanded Program on Immunization of the JE vaccine and catch-up immunisations showed a significant impact on the JE declining incidence rate. The implementation of JE immunisation programs has played a crucial role in controlling its spread. Continued efforts should be made to maintain high coverage of the JE vaccine and strengthen disease surveillance systems, ensuring JE effective control and eventual elimination.

中文翻译：

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大规模免疫消灭日本脑炎：2005-2021年贵州省的真实世界证据

探讨日本脑炎（JE）的长期流行病学变化并评估大规模免疫的影响。收集了2005年至2021年贵州省医院和县疾病预防控制中心的乙脑病例数据，根据一系列政策实施和2019冠状病毒病（COVID-19）大流行分析流行病学变化。 2005年至2021年，贵州省共报告乙脑病例5138例，死亡152例。平均发病率和病死率分别为0.83/10万和2.96%。随着年龄组发病率差距缩小、高流行地区缩小，乙脑患病率逐年呈下降趋势。在COVID-19大流行期间，乙脑活动在2020年达到最低点。将乙脑疫苗纳入扩大免疫计划和补种免疫对乙脑发病率下降产生了重大影响。乙脑免疫规划的实施，对控制乙脑传播发挥了至关重要的作用。要继续保持乙脑疫苗高覆盖率，加强疾病监测体系，确保乙脑有效控制和最终消除。