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FDA Approves New Vaccine to Prevent Japanese Encephalitis

March 30, 2009 -- The U.S. Food and Drug Administration today approved Ixiaro, a vaccine to prevent Japanese encephalitis (JE) which is caused by a mosquito-transmitted virus found mainly in Asia. IXIARO will be the only vaccine for JE available in the United States.

"This vaccine offers protection for individuals who travel to or live in areas where outbreaks are known to occur," said Karen Midthun, M.D., acting director of the FDA's Center for Biologics Evaluation and Research.

In Asia, JE affects about 30,000 to 50,000 people each year, resulting in 10,000 to 15,000 deaths. JE is rarely seen in the United States, with very few cases reported among civilians and military traveling from the United States to Asia.

The virus that causes JE affects membranes around the brain and mild infections can occur without apparent symptoms other than fever and headache. In people who develop severe disease, JE usually starts as a flu-like illness but can worsen, causing high fever, neck stiffness, brain damage, coma, or even death. The disease is transmitted via infected mosquitoes; it is not spread from human to human.

Ixiaro is a second-generation JE vaccine,in that itis manufactured using cell culture technology leading to improved manufacturing efficiency as well as more reliable control of the vaccine manufacturing process. This technology utilizes an established bank of cells that can be drawn from at any time contributing to the assurance of consistent vaccine quality.It also enhances the ability to rapidly manufacture a vaccine on a large scale if needed, without compromise to the vaccine's safety or effectiveness.

Clinical studies were conducted in more than 800 healthy men and women in the United States and Europe. Participants received either Ixiaro or Je-vax, another U.S.-licensed vaccine that is no longer being manufactured. The studies found that Ixiaro produced sufficient levels of antibodies in the blood to protect against JE. Ixiaro requires two doses instead of JE-VAX's three.

The vaccine was well tolerated and the most commonly reported adverse events were headache, muscle pain and pain, swelling, and tenderness at the injection site. Overall, it was more tolerable and had fewer side effects than the comparator, JE-VAX.

Ixiaro is manufactured by Intercell Biomedical, Livingston, U.K.

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Source: Food and Drug Administration

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