Mass vaccination in eradicating Japanese encephalitis: Real-world evidence from Guizhou Province in 2005–2021

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