IXIARO suspension for injection Japanese encephalitis vaccine (inactivated, adsorbed)


What is it and how is it used?

What IXIARO is
IXIARO is a vaccine against the Japanese encephalitis virus.

The vaccine causes the body to produce its own protection (antibodies) against this disease.

What IXIARO is used for
IXIARO is used to prevent infection with the Japanese encephalitis virus (JEV). This virus is mainly found in Asia and 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.

IXIARO should be given to adults (18 years and older).

What do you have to consider before using it?

You must NOT receive IXIARO

  • if you are allergic (hypersensitive) to the active substance or any of the other ingredients of IXIARO. The active substance and other ingredients are listed at the end of the leaflet (see Section 6 “Further Information ).
  • if you have developed an allergic reaction after receiving a former dose of IXIARO. Signs of an allergic reaction may include an itchy rash, shortness of breath and swelling of the face and tongue.
  • if you are ill with a high fever. In this case, your doctor will postpone the vaccination.

Take special care with IXIARO
IXIARO must not be injected into a blood vessel.
Primary immunization should be completed at least one week prior to potential exposure to JEV.

Tell your doctor:

  • if you have experienced any health problems after previous administration of any vaccine.
  • if you have any other known allergies.
  • if you have a bleeding disorder (a disease that makes you bleed more than normal) or a reduction in blood platelets, which increases risk of bleeding or bruising (thrombocytopenia).
  • if you are under 18. Since IXIARO has not been tested in people under 18 it is not recommended to be used in this group.
  • if your immune system does not work properly (immunodeficiency) or you are taking medicines affecting your immune system(such as a medicine called cortisone or cancer medicine).

Your doctor will discuss with you the possible risks and benefits of receiving IXIARO.

Please note that:

  • IXIARO cannot cause the disease it protects against.
  • IXIARO will not prevent infections caused by other viruses than the Japanese encephalitis virus.
  • You should take appropriate precautions to reduce mosquito bites (adequate clothing, use of repellents, mosquito nets) even after receiving IXIARO.

Using other medicines or vaccines
A study in humans to evaluate the effectiveness and safety of medicines (clinical trial) has shown that IXIARO can be given at the same time with hepatitis A vaccine.
Please tell your doctor if you are taking or have recently taken any other medicines, including medicines obtained without a prescription or have recently received any other vaccine.

Pregnancy and breast-feeding
There are limited amount of data from the use of IXIARO in pregnant or breast-feeding women. As a precautionary measure, the use of IXIARO during pregnancy or breast-feeding should be avoided. Ask your doctor or pharmacist for advice before taking any medicine.

Driving and using machines
No studies on the effect of IXIARO on the ability to drive or use machines have been preformed.

How is it used?

Dosage for adults
You will receive a total of 2 injections:

  • the first injection on Day 0
  • the second injection 28 days after the first injection (Day 28).

Make sure you finish the complete vaccination course of 2 injections. The second injection should be given at least 1 week before you will be at risk of exposure to JE virus. If not, you may not be fully protected against the disease.

A booster dose can be given within the second year (i.e. 12 - 24 months) after the first dose of the recommended primary immunization. Your doctor will decide on requirement of booster.

IXIARO is injected into your upper arm muscle (deltoid muscle) by your doctor or a nurse. It must not be injected into a blood vessel. In case you suffer from a bleeding disorder, your doctor may decide to administer the vaccine under the skin (subcutaneously).

If you have any further questions on the use of this product, ask your doctor or pharmacist.

If you forget to take IXIARO
If you miss a scheduled injection, talk to your doctor and arrange another visit for the second injection. Without the second injection you will not be fully protected against the disease. There is data that the second injection can be given up to 11 months after the first one.

What are possible side effects?

Like all medicines, IXIARO can cause side effects, although not everybody gets them.

The frequency of the side effects are defined as follows Very common affects more than 1 user in 10 Common affects 1 to 10 users in 100 Uncommon affects 1 to 10 users in 1,000 Rare affects 1 to 10 users in 10,000 Very rare affects less than 1 user in 10,000 Not known Frequency cannot be estimated from the available data

The majority of the side effects listed below have been observed during clinical trials. They usually occur within the first 3 days after vaccination, are usually mild and disappear within a few days.

Very common:

  • headache
  • muscle pain
  • tiredness
  • injection site reactions (pain, tenderness)


  • fatigue
  • nausea
  • influenza like illness
  • fever
  • injection site reactions (redness, hardening, swelling, itching)


  • vomiting
  • skin rash
  • changes in the lymph-nodes
  • migraine (throbbing headache, often accompanied by nausea and vomiting and sensitivity to light)
  • dizziness
  • vertigo (spinning sensation)
  • diarrhoea
  • belly pain
  • itching
  • chills
  • runny or blocked nose
  • inflammation of nose and throat
  • general condition of feeling unwell
  • musculoskeletal stiffness
  • injection site reactions (bleeding, bruising)
  • abnormal laboratory liver test results


  • palpitations
  • rapid heart beat
  • difficulty to breathe
  • abnormal sensation of skin
  • hives
  • skin redness
  • pain in leg or arm
  • joint pain
  • platelet deficiency
  • nerve inflammation
  • foot, leg and ankle swelling

If any of the side effects gets serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.

How should it be stored?

  • Keep out of the reach and sight of children.
  • Do not use IXIARO after the expiry date which is stated on the carton and label after “EXP”. The expiry date refers to the last day of that month.
  • Store in a refrigerator (2°C - 8°C).
  • Do not freeze. If the vaccine has been frozen it should not be used.
  • Store in the original package in order to protect from light.
  • Any unused product or waste material should be disposed of in accordance with local requirements.

What is it?

Ixiaro is a vaccine that contains inactivated Japanese encephalitis viruses as the active substance.

What is it used for?

Ixiaro is used to protect adults against Japanese encephalitis, a disease that causes inflammation of the brain. Japanese encephalitis can be fatal or lead to long-term disability. It is transmitted by mosquitoes and is most common in Asia, particularly in rural areas. Vaccination with Ixiaro should be considered for people who are at risk of exposure to the Japanese encephalitis virus through travel or work.

The medicine can only be obtained with a prescription.

How is it used?

Ixiaro should be given as two injections into the shoulder muscle, four weeks apart. It is recommended that individuals who receive the first dose of Ixiaro should complete both doses. If the second dose is missed for any reason, it can be given up to 11 months after the first.

People who are likely to be exposed to the Japanese encephalitis virus again or who are at continuous risk of the disease should receive a booster dose of Ixiaro one to two years later.

Ixiaro should never be injected into a blood vessel. It can be injected under the skin in people who have a bleeding disorder such as low blood platelet counts or haemophilia.

How does it work?

Ixiaro is a vaccine. Vaccines work by ‘teaching’ the immune system (the body’s natural defences) how to defend itself against a disease. Ixiaro contains small amounts of the viruses that cause Japanese encephalitis, which have been inactivated (killed) so that they cannot cause the disease. When a person is given the vaccine, the immune system recognises the inactivated viruses as ‘foreign’ and makes antibodies against them. In the future, the immune system will be able to produce antibodies more quickly when it is exposed to Japanese encephalitis viruses. The antibodies will help to protect against the disease.

The vaccine is ‘adsorbed’. This means that the viruses are fixed onto aluminium compounds, to stimulate a better response. Unlike other vaccines against Japanese encephalitis, which use viruses grown in mouse brains, the viruses in Ixiaro are grown in mammal cells (‘vero cells’) under laboratory conditions.

How has it been studied?

Ixiaro has been studied in one main study involving 867 healthy adults. The study compared Ixiaro with another vaccine for Japanese encephalitis containing viruses grown in mouse brains. It measured the ability of the two vaccines to trigger the production of antibodies against the Japanese encephalitis virus, four weeks after the final injection.

In addition, the company presented the results of studies looking at the level of protection for up to three years after vaccination with Ixiaro, and at the response to booster doses.

What benefits has it shown during the studies?

Ixiaro was as effective as the comparator vaccine at triggering the production of antibodies against the Japanese encephalitis virus. Before vaccination, most of the people in the study had no protective levels of antibodies against the virus. Four weeks after the final injection, 96% of these people who received both doses of Ixiaro had developed protective levels of antibodies (352 out of 365). This was compared with 94% of the people receiving the comparator vaccine (347 out of 370). On average, the levels of antibodies were over two times higher in the people receiving Ixiaro than in those receiving the comparator vaccine.

The additional studies showed that protection against Japanese encephalitis virus lasted for at least two to three years in most people vaccinated with Ixiaro. They also showed that a booster dose might be needed to maintain high levels of protection, which may be necessary for people at high risk of exposure to the virus.

What is the risk associated?

The most common side effects with Ixiaro (seen in more than 1 patient in 10) are headache, myalgia (muscle pain), and pain and tenderness at the injection site. For the full list of all side effects reported with Ixiaro, see the Package Leaflet.

Ixiaro should not be used in people who may be hypersensitive (allergic) to the active substance, any of the other ingredients or any residual substances in the vaccine such as protamine sulphate. Anyone having an allergic reaction after the first dose of Ixiaro should not receive the second dose. Vaccination should be postponed in people with a sudden, severe fever.

Why has it been approved?

The CHMP decided that Ixiaro’s benefits are greater than its risks and noted that the production of the only other vaccine for protection against Japanese encephalitis that was in use outside Asia had been discontinued. The Committee recommended that Ixiaro be given marketing authorisation.

Further information

The European Commission granted a marketing authorisation valid throughout the European Union for Ixiaro to Intercell AG on 31 March 2009. The marketing authorisation is valid for five years, after which it can be renewed.

For more information about treatment with Ixiaro, read the Package Leaflet (also part of the EPAR).

This summary was last updated in 03-2010.