Estimates of the global burden of Japanese Encephalitis and the impact of vaccination from 2000-2015

Japanese encephalitis (JE) is a mosquito-borne disease, known for its high death and disability rate among symptomatic cases. Many effective vaccines are available for JE, and the use of a recently developed and inexpensive vaccine has been increasing over the recent years particularly with Gavi support. Estimates of the local burden and the past impact of vaccination are therefore increasingly needed, but difficult due to the limitations of JE surveillance. In this study, we implemented a mathematical modelling method combined with age-stratifed case data which can overcome some of these limitations. We estimate in 2015 JE infections caused 100,308 cases (95%CI: 61,720 - 157,522) and 25,125 deaths (95%CI: 14,550 - 46,031), and that between 2000 and 2015 307,774 JE cases (95%CI: 167,442- 509,583) were averted due to vaccination. Our results highlight areas that could have the greatest benefit from starting vaccination or from scaling up existing programs and will be of use to support local and international policymakers in making vaccine allocation decisions.