Ixiaro

What is Ixiaro?

Ixiaro is an injectable vaccine. Contains inactivated (killed) Japanese encephalitis virus as an active ingredient.

What is Ixiaro used for?

Ixiaro is used to immunize adults against Japanese encephalitis, a disease that causes inflammation of the brain. Japanese encephalitis can be fatal or can cause long-lasting disability. It is transmitted by mosquitoes and is more common in Asia, mainly in rural areas. Vaccination with Ixiaro is recommended in individuals at risk of exposure to the Japanese encephalitis virus in anticipation of a trip or because of their work.
The medicine can only be obtained with a prescription.

How is Ixiaro used?

Ixiaro should be given as two injections into the shoulder muscle four weeks apart. Patients who are injected with the first dose of Ixiaro are recommended to complete their course with the second dose. The duration of protection after vaccination is not known and the possible effect of a booster vaccination is not yet known.
Ixiaro must never be injected intravascularly. It can be administered subcutaneously in people who have bleeding disorders such as low platelet counts or haemophilia.

How does Ixiaro work?

Ixiaro is a vaccine. Vaccines work by "teaching" the immune system (the body's natural defenses) to defend itself against a disease. Ixiaro contains small amounts of the viruses that cause Japanese encephalitis, previously inactivated so as not to cause the disease. When a person is vaccinated, the immune system recognizes inactivated viruses as "foreign" and makes antibodies against those viruses. Later, if you are again exposed to Japanese encephalitis viruses, your immune system will be able to produce antibodies more quickly that will help protect against the disease.
The vaccine is "adsorbed". This means that the viruses are fixed on aluminum compounds to stimulate a better response. Unlike other Japanese encephalitis vaccines, which use viruses grown in mouse brains, Ixiaro viruses are grown in mammalian cells ("Vero cells") under laboratory conditions.

How has Ixiaro been studied?

The effects of Ixiaro were first tested in experimental models before being studied in humans.
Ixiaro has been studied in one main study involving 867 healthy adults. In the study, Ixiaro was compared with another Japanese encephalitis vaccine containing viruses grown in the brains of mice. The ability of the two vaccines to trigger the production of antibodies (immunogenicity) against the Japanese encephalitis virus was measured, four weeks. after the last injection.

What benefit has Ixiaro shown during the studies?

Ixiaro was as effective as the comparator vaccine in triggering the production of antibodies against the Japanese encephalitis virus. Prior to vaccination, most of the people tested had no levels of protective antibodies against the virus. Four weeks after the last injection, 96% of these people given both doses of Ixiaro developed protective antibody levels (352 out of 365), compared with 94% of those given the comparator vaccine ( 347 out of 370) Antibody levels were much higher (on average more than double) in people treated with Ixiaro than in those treated with the comparator vaccine.

What is the risk associated with Ixiaro?

The most common side effects with Ixiaro (seen in more than 1 in 10 patients) are headache, myalgia (muscle aches) as well as pain and tenderness at the injection site. For the complete list of side effects reported with Ixiaro , see the package leaflet.
Ixiaro must not be used in people who may be hypersensitive (allergic) to the active substance, to any of the other ingredients or to any residues present in the vaccine (for example, protamine sulphate). Individuals who have developed an allergic reaction after injection of the first dose should not be given the second dose. The administration of the vaccine should be postponed in patients in acute severe febrile state.

Why has Ixiaro been approved?

The Committee for Medicinal Products for Human Use (CHMP) decided that Ixiaro's benefits are greater than its risks for active immunization against Japanese encephalitis in adults. It also noted that production of the only other vaccine in use outside Asia to protect against Japanese encephalitis has been discontinued. The committee recommended that Ixiaro be granted marketing authorization.

More information about Ixiaro

On March 31, 2009, the European Commission granted Intercell AG a "Marketing Authorization" for Ixiaro, valid throughout the European Union.
For the full version of Ixiaro's EPAR, click here.

Last update of this summary: 04-2009.

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