Japanese Encephalitis

When to book the Japanese encephalitis vaccine

The vaccine is recommended for travellers to rural areas of Asia and the Western Pacific, particularly during the rainy season. Consider it if you are:

• Travelling to rural or agricultural areas in Southeast Asia, East Asia or the Western Pacific
• Spending a month or more in an endemic area
• Visiting during the rainy season, when transmission risk peaks
• Planning trekking, cycling or camping in risk areas
• Working outdoors or in agriculture in an endemic region
• Travelling somewhere with a known outbreak

High-risk countries include India, Nepal, Bangladesh, Myanmar, Thailand, Cambodia, Laos, Vietnam, China, Japan, South Korea, Taiwan, the Philippines, Indonesia, Malaysia, Papua New Guinea and parts of northern Australia. Risk is highest near rice fields, irrigation systems and standing water. Short trips to cities carry lower risk. Start the course at least five weeks before departure.

What is Japanese encephalitis?

Japanese encephalitis is a viral infection of the brain spread by the bite of an infected Culex mosquito, which breeds in rice paddies and standing water. It cannot pass from person to person. It is rare in travellers, but severe cases cause inflammation of the brain leading to permanent neurological damage or death, and there is no specific treatment, so vaccination is the key protection.

Most infected people have no symptoms. Where symptoms occur, they appear five to fifteen days after a bite:

• High temperature and fever
• Severe headache
• Nausea, vomiting and diarrhoea
• Muscle pain and fatigue
• Confusion, seizures or altered consciousness in severe cases
• Stiff neck and sensitivity to light
• Paralysis or neurological complications in the most serious cases

Severe cases need immediate hospital treatment. If symptoms develop after returning from a risk area, seek urgent medical attention and mention your travel history.

How the vaccine works

The UK vaccine is Ixiaro, given as two doses 28 days apart, ideally completed at least one week before travel. A booster may be recommended 12 to 24 months later for those at ongoing risk. It is licensed from two months of age, with a reduced dose for children under three, and is well tolerated. Side effects are usually mild: soreness or redness at the injection site, headache, muscle pain, tiredness and mild fever.

Reducing your risk

Culex mosquitoes are most active in the evening and at night, so use insect repellent, wear long sleeves and trousers, sleep under a mosquito net, use plug-in repellent devices and choose air-conditioned accommodation where possible.

Find Japanese encephalitis vaccination near you

No GP referral needed. Travel health consultations tailored to your destination, the full range of travel vaccinations and antimalarials, and vaccination records for your travel documents. Use the postcode search above to find your nearest Allied Pharmacy.