Ixiaro: a new vaccine against Japanese encephalitis.

The mosquito-borne Japanese encephalitis virus (JEV) is a major threat to human health in Asia. An estimated 50,000 cases occur in the region, accounting for at least 10,000 deaths and 15,000 cases of neuropsychiatric sequelae. A new purified, inactivated JEV vaccine (IC51, Ixiaro) has been developed. Since early 2009, the vaccine has been licensed in Australia, the USA and Europe. A series of successful Phase III studies has been published. Results indicate a very good safety and efficacy profile. The vaccine promises to become a modern approach to active immunization against Japanese encephalitis. With the availability of a new product, wider use of Japanese encephalitis vaccine will be prudent in the future, and guidelines and recommendations should be revised.