The United States Food and Drug Administration has approved the Ixiaro vaccine for the prevention of Japanese encephalitis. The vaccine will be marketed in the U.S. as Ixiaro by Novartis Vaccines.
Japanese encephalitis is a mosquito-borne flaviviral infection that results in 10,000-15,000 deaths annually and is a potential threat for travelers to Asia. A vaccine against Japanese encephalitis has been available for travelers from the U.S., however its use has been limited by concerns over its safety profile and a recent announcement of discontinued production. Ixiaro has been shown to be as immunogenic as the currently licensed Japanese Encephalitis vaccine but with a better local tolerability profile and a more convenient dosing schedule.
The Japanese encephalitis virus is only transmitted by certain types of mosquitoes (most commonly Culex tritaeniorhynchus). These mosquitoes are usually found in rural, rice-growing, and pig farming regions of Asia, but can also be found at the outskirts of cities. The nature of the Japanese encephalitis life cycle means it is not possible to eradicate the disease.
Ixiaro is indicated for active immunization against Japanese encephalitis virus for persons 17 years of age and older. The most common systemic adverse events observed in clinical trials with Ixiaro were headache and muscle ache. The most common local reactions were pain and tenderness. Ixiaro should not be given to adults who are allergic to any of the ingredients in the vaccine, including protamine sulfate. Ixiaro will not protect against encephalitis caused by viruses/pathogens other than the Japanese encephalitis virus. Vaccination with Ixiaro may not result in protection against Japanese Encephalitis virus in all cases.