Japanese Encephalitis Prevention and Control: Advances, Challenges, and New Initiatives

Abstract

This chapter provides an overview of Japanese encephalitis (JE) epidemiology, prevention, and control and discusses recent advances, current challenges, and new initiatives in JE surveillance, diagnosis, and vaccines. Human vaccination is the most effective and sustainable measure to prevent JE. Interventions to control the mosquito vector or animal hosts may also lessen the number of human JEV infections; however, these methods have significant limitations. Urbanization, improved socioeconomic conditions, and changes in agricultural practices have contributed to significant reductions in the burden of JE in several Asian countries. There are three types of JE vaccines that are currently available. They are inactivated mouse brain-derived JE vaccine, live attenuated cell culture-derived SA 14-14-2 vaccine, and inactivated cell culture-derived P3 vaccine. Inactivated mouse brain-derived vaccines and a live attenuated cell culture-derived SA 14-14-2 vaccine are used in many countries. Inactivated cell culture-derived P3 vaccines are available only in China. Improved understanding of the epidemiology and an accurate measurement of the true JE disease burden in countries where it is endemic are needed to stimulate and guide the implementation of new vaccine strategies and policies. JE remains a significant but preventable public health problem. Substantial progress has been made in defining the true burden of illness and expanding the use of available vaccines. With sustained commitment and funding, safe, effective, and affordable JE vaccines can and should be integrated into the routine immunization programs in all areas where JE is endemic.