Who should have it
Travellers visiting rural or agricultural areas of Asia and the Western Pacific, particularly for longer stays, repeated trips, or during the wet season when mosquitoes are most active. It’s especially worth considering if you’ll be spending time outdoors or near rice fields, farmland, or wetlands.
How many doses
Protection is usually given as a course of doses before you travel, completed in good time so it can take effect. Your prescriber will confirm the exact schedule and timing based on your trip.
Possible side effects
Side effects are usually mild and may include soreness, redness or swelling at the injection site, headache, muscle aches, tiredness, or a mild temperature in the days after vaccination.
Additional precautions
The vaccine reduces your risk, but avoiding mosquito bites is still important, as the mosquitoes that spread it bite mainly between dusk and dawn. Use insect repellent, cover up in the evenings, and sleep under a net where rooms aren’t screened or air conditioned.
About the disease
Japanese encephalitis is a viral infection spread by infected mosquitoes, mainly in rural parts of Asia. Most people who are infected have no or mild symptoms, but in a small number it can cause serious inflammation of the brain, which is why prevention matters for higher risk trips.