Japanese Encephalitis Vaccine: Recommendations of the Advisory Committee on Immunization Practices

Abstract

Summary This report updates the 2010 recommendations from the CDC Advisory Committee on Immunization Practices (ACIP) regarding prevention of Japanese encephalitis (JE) among U.S. travelers and laboratory workers (Fischer M, Lindsey N, Staples JE, Hills S. Japanese encephalitis vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2010;59[No. RR-1]). The report summarizes the epidemiology of JE, describes the JE vaccine that is licensed and available in the United States, and provides recommendations for its use among travelers and laboratory workers. JE virus, a mosquitoborne flavivirus, is the most common vaccine-preventable cause of encephalitis in Asia. JE occurs throughout most of Asia and parts of the western Pacific. Approximately 20%–30% of patients die, and 30%–50% of survivors have neurologic, cognitive, or behavioral sequelae. No antiviral treatment is available. Inactivated Vero cell culture–derived JE vaccine (Ixiaro [JE-VC]) is the only JE vaccine that is licensed and available in the United States. In 2009, the U.S. Food and Drug Administration (FDA) licensed JE-VC for use in persons aged ≥17 years; in 2013, licensure was extended to include children aged ≥2 months. Most travelers to countries where the disease is endemic are at very low risk for JE. However, some travelers are at increased risk for infection on the basis of their travel plans. Factors that increase the risk for JE virus exposure include 1) traveling for a longer period; 2) travel during the JE virus transmission season; 3) spending time in rural areas; 4) participating in extensive outdoor activities; and 5) staying in accommodations without air conditioning, screens, or bed nets. All travelers to countries where JE is endemic should be advised to take precautions to avoid mosquito bites to reduce the risk for JE and other vectorborne diseases. For some persons who might be at increased risk for JE, the vaccine can further reduce the risk for infection. The decision about whether to vaccinate should be individualized and consider the 1) risks related to the specific travel itinerary, 2) likelihood of future travel to countries where JE is endemic, 3) high morbidity and mortality of JE, 4) availability of an effective vaccine, 5) possibility (but low probability) of serious adverse events after vaccination, and 6) the traveler’s personal perception and tolerance of risk. JE vaccine is recommended for persons moving to a JE-endemic country to take up residence, longer-term (e.g., ≥1 month) travelers to JE-endemic areas, and frequent travelers to JE-endemic areas. JE vaccine also should be considered for shorter-term (e.g., <1 month) travelers with an increased risk for JE on the basis of planned travel duration, season, location, activities, and accommodations and for travelers to JE-endemic areas who are uncertain about their specific travel duration, destinations, or activities. JE vaccine is not recommended for travelers w...

Twenty Years of Progress Toward West Nile Virus Vaccine Development

“…Due to the similarity of JEV and WNV, consideration of the animal models used for JEV vaccine testing can provide insight for WNV vaccine development. Mice are the most broadly used model to determine protective efficacy of JEV vaccines, as they generate neutralizing antibody responses upon vaccination and most mouse strains are highly susceptible to WT JEV, so peripheral challenge can adequately assess protection [36,52]. Many studies have demonstrated that JEV inactivated and live, attenuated vaccines in mice induce neutralizing antibody titers that correlate with survival from WT virus challenge [53,54,55,56,57], and the antibodies can provide protection against multiple JEV genotypes [56,57].…”

Long-term neurological and healthcare burden of adults with Japanese encephalitis: A nationwide study 2000-2015

“…In areas with endemic JE, the virus primarily affects children, with the vast majority of cases being children aged < 15 years [3][4][5][6][7][8][9][10][11][12]. As there is no effective antiviral treatment, vaccination is the only approach for preventing this virus [13]. In areas with childhood JE vaccination, although the overall incidence of JE has decreased, a greater proportion of adults affected by JE has been reported, predominantly in temperate Asian countries (e.g., Japan, China, South Korea) [14][15][16][17][18][19][20][21][22].…”

Vector-borne diseases in pregnancy

“…IXIARO ® -an inactivated VERO cell cultured JEV vaccine -is now immunogenic and safe in children >2 months old and should be considered in those, including women of childbearing age, travelling to endemic areas. 80,81 Togaviruses: Chikungunya Chikungunya virus (CHIKV) is a non-flavivirid mosquito-borne infection that causes significant morbidity and, on occasion, mortality. CHIKV is a Togavirus first described in the 1950s that has spread from Africa to the Indian Ocean and Asia.…”

“…IXIARO® – an inactivated VERO cell cultured JEV vaccine – is now immunogenic and safe in children >2 months old and should be considered in those, including women of childbearing age, travelling to endemic areas. 80 , 81 …”