Vaccine Info

Japanese Encephalitis Vaccines

Japanese Encephalitis

Japanese Encephalitis Virus (JEV) is a flavivirus that is the main cause of viral encephalitis in many countries of Asia with an estimated 68,000 clinical cases every year. There are safe and effective vaccines are available to prevent JE.

Japanese Encephalitis Vaccines

JE vaccine is recommended for persons moving to a JE-endemic country to live, longer-term travelers, and frequent travelers to JE-endemic areas. JE vaccine also should be considered for shorter-term (e.g., less than 1 month) travelers with an increased risk of JE based on planned travel duration, season, location, activities, and accommodations. Vaccination also should be considered for travelers to endemic areas who are uncertain of a specific duration of travel, destinations, or activities, says the CDC.

JE vaccines are not recommended for travelers with very low-risk itineraries, such as shorter-term travel limited to urban areas or travel that occurs outside of a well-defined JE virus transmission season. But, It is believed that infection in a pregnant woman could harm her unborn baby.

  • JENVAC is an inactivated vero cell-derived vaccine prepared from an Indian Kolar strain of the Japanese encephalitis virus.
  • Ixiaro is an inactivated, adsorbed Vero cell culture-derived vaccine. It is prepared by propagating JEV strain SA14-14-2 in Vero cells. Multiple viral harvests are pooled, clarified and concentrated. The virus suspension is treated with protamine sulfate to remove contaminating DNA and proteins. 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 various countries, but are not licensed for use in the USA.

Studies have shown that severe reactions to the JE vaccine are very rare. As with any medicine, there is a very remote chance of a vaccine causing a severe allergic reaction, other serious injuries, or death.

Japanese Encephalitis Overview

Japanese encephalitis is rare, the case-fatality rate among those with encephalitis can be high. Permanent neurologic or psychiatric sequelae can occur in 30%–50% of those with encephalitis. 

There is no cure for the disease.

JEV treatment is focused on relieving severe clinical signs and supporting the patient to overcome the infection. Treatment is symptomatic. Rest, fluids, and use of pain relievers and medication to reduce fever may relieve some symptoms.

It is spread through the bite of an infected mosquito. It does not spread from person to person. 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 (swelling of the brain). A person with encephalitis can experience fever, neck stiffness, seizures, and coma says the CDC.

Japanese Encephalitis vaccine content is sourced from the World Health Organization, the US Centers for Disease Control and Prevention,, and news published by Precision Vaccinations.


09/28/2020 - 09:13