Japanese Encephalitis Vaccination

Understanding Japanese Encephalitis Vaccination

Japanese Encephalitis (JE) is a serious infection caused by the Japanese encephalitis virus, a flavivirus related to dengue, yellow fever, and West Nile viruses. It is transmitted by the bite of infected mosquitoes and is found mainly in rural and agricultural areas in Asia and the Western Pacific. The global prevalence of JE is significant, with approximately 68,000 clinical cases reported annually, though many cases may go unreported.

Prevention

The Japanese Encephalitis Vaccination is a critical preventive measure, especially for travelers to endemic regions. The vaccine is typically administered in a two-dose series, with the doses spaced 28 days apart. For rapid protection, adults aged 18–65 years may receive the second dose as early as 7 days after the first. It is recommended to complete the vaccination course at least one week before travel to allow for an adequate immune response.

Countries at Risk

Regions where JE is most commonly found include parts of Southeast Asia, the Indian subcontinent, East Asia, and the Pacific islands. Travelers to these areas should consider vaccination, particularly if they plan to spend time in rural or outdoor settings. Find country-specific vaccine recommendations with Travel Health Pro.

Signs and Symptoms

The majority of JE virus infections are mild (fever and headache) or without apparent symptoms, but approximately 1 in 250 infections results in severe clinical illness. The severe disease is characterized by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures, spastic paralysis, and ultimately can lead to death. Up to half of the survivors have persistent neurological sequelae.