Japanese encephalitis (JE; inflammation of the brain) is caused by the Japanese encephalitis virus and is transmitted to humans via Culex mosquitoes (Culex Vishnui Complex, C.Tritaeniorrhynchus, C. gelidus in the tropics). This virus is found predominantly in eastern Russia, Japan, China, India, Pakistan, and Southeast Asia.
Japanese encephalitis vaccination in Germany is performed with an inactivated vaccine (formol-inactivated JEV strain SA 14-14-2).
The inactivated vaccine has been licensed for adults since 2009 and for children older than two months since 2013, with special dosing requirements for children aged two months to three years.
Indications (areas of application)
- R: Vaccinations due to travel: Stays in endemic areas (Southeast Asia, large parts of India, Korea, Japan, China, Western Pacific, Northern Australia) during the transmission period, especially in:
- Travel to current outbreak areas
- Long-term stay (>4 weeks)
- Repeated short-term stays
- Foreseeable stay near rice fields and pig farming (not limited to rural areas).
- B: Vaccination due to increased occupational risk: laboratory personnel specifically working with wild-type strains of JEV capable of replication.
Legend
- B: Vaccinations due to an increased occupational risk, e.g., after risk assessment in accordance with the Occupational Health and Safety Act/Biological Substances Ordinance/Ordinance on Occupational Medical Precautions (ArbMedVV) and/or for the protection of third parties in the context of occupational activities.
- R: Vaccinations due to travel
Contraindications
- Pregnant women
- People who are currently going through an infectious disease
- People with congenital or acquired immunodeficiencies such as HIV infection.
- Individuals with adverse reactions to previous vaccination with the same vaccine
- Allergy to vaccine components (see manufacturer’s supplements).
Implementation
- Basic immunization:
- Adults: basic immunization in adults consists of 2 doses of 0.5 ml at 4-week intervals or at 1-week intervals (rapid schedule: d 0 and d 7, approved for use from 18-65 years).
- Children: For children aged 2 months-3 years, 2 doses of 0.25 ml are given 4 weeks apart. From the age of 3 years, full vaccine doses of 0.5 ml are given
- Booster vaccination:
- Booster dose before re-exposure, no earlier than 12 months after basic immunization.
- In case of continued risk of exposure, the 1st booster is given 12-24 months after basic immunization, and a 2nd booster is recommended 10 years after the 1st booster if the indication persists.
Effectiveness
- Reliable efficacy Vaccine protection from circa one week after the 2nd partial vaccination.
Side effects / vaccination reactions
- Anaphylaxis
- Allergic reactions
Caveat. Individuals receiving Japanese encephalitis vaccination should be observed for ten days!
