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Japanese Encephalitis

Pronounced (in-cef-a-LY-tis)

One of the Non-routine Vaccines by Disease


Japanese encephalitis (JE) is a serious infection caused by the Japanese encephalitis virus.

  • It occurs mainly in rural parts of Asia.
  • It is spread through the bite of an infected mosquito. It does not spread from person to person.
  • Risk is very low for most travelers. It is higher for people living in areas where the disease is common, or for people traveling there for long periods of time.
  • Most people infected with JE virus don’t have any symptoms. Others might have symptoms as mild as a fever and headache, or as serious as encephalitis (brain infection).
  • A person with encephalitis can experience fever, neck stiffness, seizures, and coma. About 1 person in 4 with encephalitis dies. Up to half of those who don’t die have permanent disability.
  • It is believed that infection in a pregnant woman could harm her unborn baby.
  • JE vaccine can help protect travelers from JE disease.
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