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Travel health.
Clearly explained.

Japanese encephalitis vaccine

Japanese encephalitis vaccination can reduce risk from a mosquito-borne brain infection in selected travellers to Asia and the western Pacific.

What is it?

Most infections cause no symptoms, but encephalitis can cause seizures, permanent neurological disability or death.

Where it may be relevant

  • Long-stay travellers in risk areas during transmission season
  • People spending substantial time in rural, rice-growing or pig-farming areas
  • Travellers with extensive outdoor or night-time exposure, even on shorter trips

Dose schedules.

The clinician will select the appropriate licensed schedule after reviewing age, health, previous doses and departure date.

Standard course

Age 3 years and over

Dose 1Day 0
Dose 2Day 28

Rapid adult course

Eligible adults aged 18–65

Dose 1Day 0
Dose 2Day 7

Complete the course at least seven days before exposure.

Booster

Continuing risk

Dose 112–24 months

Timing depends on age, previous course and continuing exposure.

Who may be eligible

  • Adults and children from the licensed minimum age whose itinerary creates sufficient risk
  • People needing a booster because continuing exposure is expected

Who may not be eligible

  • Anyone with a confirmed severe allergic reaction to a previous dose or a vaccine ingredient
  • People who are acutely unwell with a significant fever may need vaccination deferred
  • Pregnancy, breastfeeding, immune suppression and current medicines must be reviewed individually

Potential side effects

  • Pain, redness or swelling where the injection is given
  • Headache, tiredness, muscle aches or a mild fever
  • Feeling faint around the time of vaccination

Important risks and precautions

  • A severe allergic reaction is very rare and requires urgent treatment
  • Protection is not absolute, so relevant food, water, bite or exposure precautions remain important
  • The exact product and schedule must be confirmed during a clinical assessment

Clinical references

Further information.

Information is general and does not replace a personal assessment, prescribing decision or the latest destination-specific advice.

Frequently asked questions

What does the Japanese encephalitis vaccine protect against?

It reduces the risk of Japanese encephalitis but mosquito precautions remain essential.

Who should consider the Japanese encephalitis vaccine?

It is mainly considered for longer, rural or high-exposure itineraries in affected parts of Asia and the western Pacific.

How many doses of the Japanese encephalitis vaccine are needed?

The primary course is usually two doses; eligible adults may use a rapid day 0 and day 7 schedule.

Can I have the Japanese encephalitis vaccine close to departure?

Book an assessment even when departure is close. Whether vaccination can be completed or still provide useful protection depends on the product, previous doses and time available.

Can the Japanese encephalitis vaccine be given with other vaccines?

Many vaccines can be given at the same appointment, but spacing rules can apply to some live vaccines. The clinician will check the products, your history and the proposed schedule.