What Is Japanese Encephalitis?

Japanese encephalitis is a serious viral infection transmitted through mosquito bites. While many people experience no symptoms, others can develop life-threatening complications, such as swelling of the brain (encephalitis), permanent neurological damage, or even death.

It is most commonly found in rural and agricultural areas, particularly near rice paddies and pig farms, where mosquito populations are high.

Symptoms of Japanese Encephalitis

Symptoms usually develop between 5–15 days after a mosquito bite, and may include:

• High fever
• Severe headache
• Nausea and vomiting
• Seizures
• Stiff neck
• Muscle weakness
• Confusion or disorientation
• Coma in severe cases

There is no cure or specific antiviral treatment—only supportive care. That’s why prevention through vaccination and mosquito avoidance is essential for travellers.

Do I Need the Japanese Encephalitis Vaccine?

The JE vaccine is recommended if you’re:

• Travelling to endemic areas in Asia or the Western Pacific
• Staying for more than a month in affected countries
• Visiting rural or agricultural regions, including rice fields or pig farms
• Participating in outdoor activities such as trekking, camping, or cycling
• Visiting during peak transmission seasons (monsoon or post-monsoon periods)

Even shorter trips may warrant vaccination if you’re at increased risk due to activities or local outbreaks.

Destinations at Risk

Countries with reported Japanese encephalitis cases include:

• Thailand, Vietnam, Laos, Cambodia, India, Sri Lanka
• Japan, China, South Korea, Nepal, Indonesia, Malaysia
• Myanmar (Burma), Philippines, Singapore

Always check the current risk level before you travel. Transmission can vary by season and region.

How the Japanese Encephalitis Vaccine Works

The Japanese encephalitis vaccine triggers your immune system to produce antibodies that protect you from the virus. Once vaccinated, your body is better equipped to fight off infection if exposed during travel.

• Two doses are required, spaced 28 days apart
• The full course should be completed at least 1 week before departure
• A booster dose may be recommended for long-term or repeat travel

Our pharmacists at Blackpool Express Chemist will advise you on the best timing and plan for your trip.

How Long Does Protection Last?

Protection is expected to last between 12 and 24 months. A booster dose after one year can extend this coverage if you remain at risk or plan further travel.

Japanese Encephalitis Vaccine Side Effects

The vaccine is safe and well-tolerated. Side effects are typically mild and short-lived, such as:

• Redness or swelling at the injection site
• Low-grade fever
• Muscle aches or tiredness
• Headache

Severe allergic reactions are extremely rare. Always let your pharmacist know if you’ve had previous allergic reactions to vaccines.

How to Prevent Japanese Encephalitis

In addition to the vaccine, reduce your risk with mosquito bite prevention:

• Use insect repellent with DEET or icaridin
• Wear long sleeves and trousers, especially at dawn and dusk
• Sleep under mosquito nets or in air-conditioned rooms
• Avoid stagnant water where mosquitoes breed

These measures provide added protection alongside vaccination.