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Ixiaro Vaccine

Generic name: japanese encephalitis vaccine, inactivated, adsorbed

What is Ixiaro Vaccine?

  • Ixiaro is a vaccine for use in individuals 2 months of age and older to help protect against Japanese encephalitis (JE). You cannot get the disease from Ixiaro.
  • You will need 2 doses of the vaccine.
  • You should consult your health care provider on the need for a booster dose of Ixiaro
  • You should still protect yourself from mosquito bites even if you have had the Ixiaro vaccine.
  • Ixiaro may not fully protect everyone who gets the vaccine.
  • Ixiaro does not protect against encephalitis caused by other viruses/pathogens.
  • Ixiaro does not protect against other diseases transmitted by mosquitoes.

What is Japanese encephalitis virus (JEV) and what is the disease caused by JEV?

Japanese encephalitis (JE) is caused by the Japanese encephalitis virus, JEV, which is mainly found in Asia. JEV is transmitted to humans by mosquitoes that have bitten an infected animal (like pigs). Many infected people develop mild symptoms or no symptoms at all. In people who develop severe disease, JE usually starts as a flu-like illness, with fever, chills, tiredness, headache, nausea, and vomiting. Confusion and agitation also occur in the early stage. JE causes death in one out of every three people with overt encephalitis. One out of two survivors develops permanent brain damage. JE acquired during pregnancy may cause intrauterine infection and miscarriage.

Who is at risk for Japanese encephalitis?

  • People who live in, or travel to, areas where JEV circulates.
  • Laboratory personnel who work with JEV.

Who should not take Ixiaro Vaccine?

You should not get Ixiaro if you:

  • are allergic to any of the ingredients in the vaccine. A list of ingredients can be found at the end of this guide.
  • had an allergic reaction after getting a dose of the vaccine or any other JEV vaccine.

Ixiaro is not approved for use in infants below the age of 2 months.

What should I tell my healthcare provider before taking Ixiaro Vaccine?

It is very important to tell your health care provider if you:

  • have had an allergic reaction to a previous dose of Ixiaro or any other JEV vaccine.
  • have a bleeding disorder or a reduction in blood platelets, which increases risk of bleeding or bruising (thrombocytopenia) and cannot receive injections in the arm.
  • have a weakened immune system, for example, due to a genetic defect or HIV infection.
  • are or may be pregnant, or are breast feeding. Ixiaro has not been studied in pregnant women or nursing mothers.
  • currently have any illness with a fever of more than 100°F (37.8°C).
  • take any medicines, even those you can buy over the counter.

How should I take Ixiaro Vaccine?

Ixiaro is given as an injection in the upper arm muscle in individuals 3 years of age and older. Infants 2 to 11 months of age are given the vaccine into the thigh. Children 12 to 35 months of age may be given the vaccine into the arm muscle (if the muscle is large enough) or into the thigh.

You will get a total of 2 doses of the vaccine. Ideally, the doses are given as:

  • First dose: at a date you and your health care provider choose.
  • Second dose: 28 days after the first dose.

Make sure that you get both doses. If you miss the second dose, your health care provider will decide when to give the missed dose. Be aware that protection is not reliable until 1 week after you receive the second dose of Ixiaro.

Adults 18 years of age and older: if the second dose was administered more than 1 year ago, you should consult your health care provider on the need for a booster dose of Ixiaro prior to potential re-exposure to JEV.

What are the possible side effects of Ixiaro Vaccine?

The most common side effects in adolescents >12 years of age and adults are headache, muscle pain and injection site reactions (e.g., pain, swelling, tenderness, redness). Nausea, skin rash, fatigue, flu-like illness, fever, irritability and loss of appetite may also occur.

The most common side effects in children below the age of 12 years are fever, irritability, diarrhea, vomiting, loss of appetite, injection site pain and injection site redness.

Contact your health care provider right away if you get any symptoms after receiving IXIARO that concern you.

Tell your health care provider if you have any of the following problems because these may be signs of an allergic reaction:

  • difficulty breathing
  • hoarseness or wheezing
  • hives
  • dizziness, weakness or fast heart beat

General information about the safe and effective use of Ixiaro Vaccine

This guide is a summary of information about Ixiaro. If you would like more information, please talk to your health care professional.U.S.and international agencies (such as and also provide additional information about JEV and related travel advisories.

What are the ingredients in Ixiaro Vaccine?

Active Ingredient: purified components of inactivated Japanese encephalitis virus (JEV).

Inactive Ingredients: aluminum hydroxide and phosphate buffered saline (sodium chloride, potassium dihydrogen phosphate, disodium hydrogen phosphate).

Minute amounts of other substances remain in the vaccine as a result of the manufacturing process. Refer to the package insert for a complete list.

Source: National Library of Medicine. Last updated March 31, 2017.