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Japanese Encephalitis (JE)

Vaccines to Prevent Japanese Encephalitis

  • Ixiaro: Japanese Encephalitis (JE) vaccine (SpanishSite exit disclaimer) (PDF - 285KB)

The Japanese encephalitis (JE) vaccine (manufactured as IXIARO) is the only JE vaccine licensed and available in the United States. This vaccine was approved in March 2009 for use in people aged 17 years and older and in May 2013 for use in children 2 months through 16 years of age. Other JE vaccines are manufactured and used in other countries but are not licensed for use in the United States.

IXIARO is given in 2 doses:

  • Doses are spaced 28 days apart.
  • The last dose should be given at least 1 week before travel. 
  • For adults and children aged ≥3 years, each dose is 0.5 mL.
  • For children aged 2 months through 2 years, each dose is 0.25 mL.
  • For persons aged 17 years and older, a booster dose may be given if a person received the JE vaccine more than a year ago and there is a continued risk for JE virus infection or potential for re-exposure. Although studies are being conducted on the need for a booster dose for children, data are not yet available.

For more information, visit the CDC's Japanese Encephalitis Vaccine site.

Last reviewed: November 2012

What is Japanese Encephalitis (JE)?

Japanese encephalitis (JE) is a serious infection caused by a virus. It occurs mainly in rural parts of Asia.

JE virus spreads through the bite of infected mosquitoes. It cannot spread directly from person-to-person. The risk of JE is very low for most travelers, but it is higher for people living or traveling for long periods in areas where the disease is common.

Most people infected with JE virus don’t have any symptoms at all. For others, JE virus infection can cause illness ranging from fever and headache to severe encephalitis (brain infection).

Symptoms of encephalitis are fever, neck stiffness, seizures, changes in consciousness, or coma.

About one person in four with encephalitis dies. Of those who don’t die, up to half may suffer permanent brain damage. There is some evidence that an infection in a pregnant woman can harm her unborn baby.

Who gets Japanese Encephalitis (JE)?

Residents of rural areas in endemic locations, active duty military deployed to endemic areas, and visitors to these rural areas are at higher risk for Japanese Encephalitis (JE). Japanese encephalitis does not usually occur in urban areas.

Travelers to parts of Asia are at higher risk for JE, and should ask their providers about vaccination before traveling.

Ready to get Vaccinated?

Read more about the Japanese Encephalitis Vaccine:

Going to get Vaccinated:


  • Japanese Encephalitis (JE) is more common in some countries than others. Find out if you should be vaccinated before you travel abroad.