A severe infection of the brain and spinal cord caused by the bite of a Culex mosquito carrying the JE virus. The disease is most common in rural, agricultural areas of east and southeast Asia (e.g., Okinawa, Burma, Cambodia, Laos, Thailand) where mosquito larvae inhabit flooded rice fields and marshes. These mosquitoes feed outdoors from dusk until dawn. Transmission is highest in summer and fall.
Japanese encephalitis is not transmitted from person-to-person. It is the leading cause of viral encephalitis in Asia with 30,000 to 50,000 cases reported annually.
IXIARO® is an inactivated virus vaccine injected intramuscularly in a two-dose series. Doses are administered on day zero (the day of initial immunization) and on day twenty-eight. All patients receive 0.5 mL per dose. The IXIARO® series should be completed at least 1 week prior to potential exposure to JEV. The need for and timing of booster doses is not known at this time.
You cannot use IXIARO® as a booster dose for previously administered JE-Vax®. Explain to the patient that their previous doses of JE-Vax® are void and they will have to complete the two dose series of IXIARO® administration for protection against JE.
The most common side effects are headache, muscle pain and injection site reactions (e.g., pain, swelling, tenderness, redness). Nausea, skin rash, fatigue, flu-like illness, and fever may also occur. Contact your health care provider if you have any of the following problems because these may be signs of an allergic reaction:
Tell your doctor if you have any severe allergies. People who have had a severe reaction or developed a severe allergic reaction to a previous dose of JE-Vax® or IXIARO® should not be revaccinated.
Pregnant women should generally not receive JE vaccine. Check with your doctor since it could be recommended under certain circumstances.
If you will be traveling for fewer than 30 days, especially if you will be staying in major urban areas, tell your doctor. You may be at lower risk and not need the vaccine.
Anyone who has a life-threatening allergy to any component of IXIARO® should not get the vaccine. IXIARO® contains protamine sulfate, known to cause hypersensitivity reactions in some individuals. Safety and effectiveness of IXIARO® has not yet been established in pregnant women or nursing mothers.
You should tell your health care provider if you:
People with multiple allergies, especially those with a history of allergic urticaria (hives), are at higher risk for allergic complications after JE immunization. Under normal circumstances, those immunized should not travel internationally within 10 days of immunization because of the possibility of delayed allergic reactions that may require medical attention. At this time no other precautions are recommended for IXIARO®.
Temporary flying restrictions are per Service specific policy.
Currently the safety and effectiveness of IXIARO® for the pediatric population has not been established. The FDA has ongoing studies, the FDA-approved IXIARO® is only for use in patients 17 years of age or older.
JE-VAX®, the only vaccine for those younger than 17 years of age, is no longer available. ACIP guidelines suggest the following options for obtaining JE vaccine for U.S. children deemed at risk for JE exposure.