A new inactivated Japanese encephalitis vaccine for adult travelers.

Current guidelines for Japanese encephalitis (JE) vaccine relate to an older mouse brain derived vaccine with an uncertain history of adverse events including delayed anaphylaxis. JE is widely distributed, including in urban areas. Underreporting is likely in many endemic countries, and atypical clinical forms exist. A new JE vaccine produced in Vero cells has become available, which appears equi-efficacious to the mouse brain derived vaccine. In development trials the new JE vaccine was as well tolerated as placebo. A review of existing guidelines for JE vaccine use in travelers should be considered.