Japanese Encephalitis Vaccine
Class: Vaccines
ATC Class: J07BA01
VA Class: IM100
Brands: Ixiaro
Introduction
Inactivated virus vaccine. Commercially available in US as Japanese encephalitis vaccine inactivated adsorbed, an inactivated Vero cell culture-derived vaccine (JE-VC; Ixiaro). Other inactivated Japanese encephalitis vaccines (e.g., inactivated mouse brain-derived vaccine; JE-MB) and live, attenuated or live, chimeric Japanese encephalitis vaccines may be available in Asia or elsewhere.
Uses for Japanese Encephalitis Vaccine
Prevention of Disease Caused by Japanese Encephalitis Virus
Prevention of disease caused by Japanese encephalitis virus in adults, adolescents, and children 2 months of age or older. Used to stimulate active immunity against Japanese encephalitis virus in travelers and other individuals (e.g., laboratory personnel) at risk of exposure to the virus.
Japanese encephalitis virus, a Flavivirus closely related to West Nile virus (WNV), St. Louis and Murray Valley encephalitis viruses, yellow fever virus, and dengue virus, is transmitted to humans through the bite of infected mosquitoes that acquired the virus by biting infected vertebrate hosts (usually pigs or wading birds). Humans are incidental or dead-end hosts for Japanese encephalitis virus since level or duration of viremia usually insufficient to infect mosquitoes. Direct person-to-person transmission of the virus does not occur; however, intrauterine transmission from mother to child during pregnancy can occur and transmission through blood products or transplanted organs theoretically could occur.
Endemic transmission of Japanese encephalitis virus reported in ≥24 countries in Southeast Asia and Western Pacific. Although infection with the virus usually results in asymptomatic or mild disease (fever, headache, aseptic meningitis), 1 out of every 200–250 infections results in severe disease (rapid onset of high fever, headache, vomiting, generalized weakness, neck stiffness, disorientation, seizures, spastic paralysis, coma, death). In areas where the virus is endemic, approximately 30,000–68,000 cases of Japanese encephalitis reported annually; case fatality rate is approximately 20–30% and 30–50% of survivors have permanent neurologic or psychiatric sequelae.
For most travelers to Asia, risk of acquiring Japanese encephalitis virus is very low, but varies depending on location and duration of travel, season, and traveler's expected activities. Overall incidence of Japanese encephalitis among individuals from nonendemic countries traveling in Asia is estimated to be <1 case per 1 million travelers. Although risk considered minimal for most short-term travelers (traveling for <1 month) who only visit urban areas in Asia, risk for travelers who stay for prolonged periods in rural areas where active transmission of Japanese encephalitis virus is occurring and short-term or recurrent travelers who have extensive outdoor or nighttime exposure in rural areas during periods of active transmission of the virus is probably similar to risk in susceptible resident populations.
Risk of transmi...
