Reviewed by a GPhC-registered Pharmacist at Newdays Pharmacy
Quick Answer: Japanese encephalitis is a serious mosquito-borne viral brain infection endemic in parts of South, Southeast, and East Asia. The vaccine is recommended for travellers spending significant time in rural areas of risk, particularly during or after the monsoon season. It is not usually necessary for short stays in major cities. Your travel health pharmacist will advise based on your specific itinerary.
What Is Japanese Encephalitis?
Japanese encephalitis (JE) is a viral infection of the brain caused by Japanese encephalitis virus, which is transmitted through the bite of infected Culex mosquitoes. The mosquitoes that carry Japanese encephalitis typically breed in flooded rice paddies and near pig farms, which is why risk is predominantly rural and agricultural.
Most people infected with Japanese encephalitis virus experience no symptoms or only mild illness. However, approximately one in 250 infections progresses to encephalitis (brain inflammation), which is serious and has a case fatality rate of approximately 20 to 30 percent. Survivors may be left with permanent neurological disability.
Where Is Japanese Encephalitis Found?
Japanese encephalitis is present across much of South, Southeast, and East Asia. Countries with known transmission include China, India, Japan, South Korea, Nepal, Bangladesh, Sri Lanka, Thailand, Vietnam, Cambodia, Laos, Myanmar, Malaysia, Indonesia, the Philippines, Papua New Guinea, and parts of Australia (the Torres Strait Islands).
Transmission is highest during and after the monsoon season, typically between May and October in most affected countries, though this varies by region. In tropical areas, transmission may occur year-round.
Who Should Have the Japanese Encephalitis Vaccine?
The Japanese encephalitis vaccine is recommended for:
- Travellers spending a month or more in endemic areas during the transmission season
- Travellers visiting rural or agricultural areas of endemic countries regardless of trip length, where significant outdoor exposure is expected
- Travellers making repeated trips to endemic areas
- Expatriates or long-term workers living in endemic regions
- Travellers to endemic areas who plan extensive outdoor activities such as cycling, camping, or trekking
It is not generally recommended for:
- Travellers visiting major cities only with brief rural exposure
- Short-stay (under four weeks) urban travellers in most endemic countries
The Japanese Encephalitis Vaccine Available in the UK
In the UK, the available Japanese encephalitis vaccine is Ixiaro (IXIARO), which is an inactivated Vero cell culture-derived vaccine.
- Primary course: Two doses given 28 days apart
- A rapid schedule of two doses seven days apart can be used for last-minute travellers aged 18 to 65 years
- Booster: A single booster dose is recommended 12 to 24 months after the primary course if travel to risk areas continues
- Age suitability: Licensed for adults and children from two months of age
How Long Before Travel Should I Get the Japanese Encephalitis Vaccine?
The standard two-dose course requires 28 days between doses. You should therefore begin vaccination at least five to six weeks before departure to allow the second dose to be given and immunity to develop. The rapid schedule (doses seven days apart) is available for adults who are travelling at short notice, though the standard schedule is preferred where time allows.
Other Prevention Measures for Japanese Encephalitis
Even with vaccination, mosquito bite prevention measures are important, as the vaccine is not 100 percent protective and there are other mosquito-borne diseases with no vaccine available. Use DEET-based mosquito repellent (at least 50 percent DEET), wear long-sleeved clothing and long trousers in the evenings and at night, sleep under a permethrin-treated bed net, and stay in air-conditioned or well-screened accommodation where possible.
Book Your Japanese Encephalitis Vaccine in Windsor, Twyford, or Reading
Newdays Pharmacy provides Japanese encephalitis vaccination as part of our comprehensive travel health clinic service at our Eton (Windsor) and Twyford branches. Our GPhC-registered travel health pharmacists will assess whether vaccination is appropriate for your destination and itinerary.
Book Now: Book a Travel Clinic Appointment
Frequently Asked Questions
Is the Japanese encephalitis vaccine available on the NHS?
Japanese encephalitis vaccine is not routinely available on the NHS and is obtained as a private travel health service. It is available at registered travel clinics including Newdays Pharmacy.
Do I need the Japanese encephalitis vaccine for a holiday in Bali?
Bali, Indonesia is within the endemic area for Japanese encephalitis. Vaccination is recommended for travellers spending extended time in rural or agricultural areas. Short-stay urban or beach resort visitors with no rural exposure are generally considered lower risk. Your travel health pharmacist will advise based on your exact itinerary.
Can children have the Japanese encephalitis vaccine?
Yes. Ixiaro is licensed for children from two months of age. The dose used for children aged two months to two years differs from the adult dose. Discuss with your travel health pharmacist.
Clinical Disclaimer: This article is intended for general information only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any treatment or medication. Information is accurate as of the date of publication and reviewed by a GPhC-registered pharmacist.