Japanese Encephalitis Vaccine
What is Japanese Encephalitis (JE)?
Japanese encephalitis is a serious mosquito-borne infection caused by the Japanese encephalitis virus (JEV). JEV is a flavivirus, closely related to dengue, Zika, yellow fever, and West Nile viruses.
JE is the leading cause of viral encephalitis in Asia, with an estimated 100,000 clinical cases annually worldwide and around 25,000 deaths. The disease primarily affects children under 15 years of age, as most adults in endemic countries acquire natural immunity through childhood exposure.
JE is endemic in 24 countries across Asia and the Western Pacific, exposing more than 3 billion people to infection. High-risk areas include rural agricultural regions, particularly near rice fields or pig farms.
Signs and Symptoms of Japanese Encephalitis
Symptoms can take 5–15 days to appear. Most people infected with Japanese encephalitis show no symptoms.
Less than 1% of infected people develop encephalitis (brain swelling), which is fatal in about 20–30% of severe cases.
Early Symptoms
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Fever
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Headache
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Vomiting
Severe Symptoms
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Coma
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Seizures
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Stiff neck
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Confusion
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General weakness
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Movement disorders
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Mental or behavioural changes
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Paralysis (inability to move)
Complications: Severe cases can lead to long-term neurological or cognitive damage, including hearing or vision loss, speech or memory problems, and weakness of the limbs.
How is Japanese Encephalitis Transmitted?
Japanese encephalitis is spread through mosquito bites, mainly in rural and agricultural areas, especially near rice fields and pig farms.
Humans are dead-end hosts, meaning they do not spread the virus to mosquitoes.
Risks of Being Infected with Japanese Encephalitis
Geographic Risk
Japanese encephalitis occurs in:
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Almost all Asian countries
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Parts of the Western Pacific
It is most common in rural agricultural areas with rice fields and irrigation systems.
Seasonal Risk
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Temperate regions (China, Japan, Korea) – Summer and fall
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Tropical/subtropical regions (Vietnam, Thailand, Malaysia, Indonesia, Singapore) – Year-round
Mosquito Activity:
Bites occur primarily from sunset to sunrise
Who is Most at Risk?
Most travellers have low risk, especially those staying in cities.
Higher-risk travellers include:
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Visiting rural or agricultural areas for longer than 1 month
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Doing outdoor activities: hiking, cycling, camping, or fieldwork
Higher-risk populations:
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Infants and the elderly are more likely to develop severe disease
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Severe JE is fatal in 20–30% of cases
How is the Japanese Encephalitis Vaccine Given?
IXIARO® (Inactivated Vero cell culture-derived vaccine)
Primary Series:
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Children 2 months–<3 years: 0.25 mL, intramuscular, 2 doses 28 days apart
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Individuals ≥3 years: 0.5 mL, intramuscular, 2 doses 28 days apart
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Accelerated schedule (days 0 and 7) may be used if travel is imminent
Booster:
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Recommended ≥1 year after primary series if ongoing risk exists
Timing:
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Complete the 2-dose series ≥1 week before travel
Safety:
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Common reactions: injection site pain, headache, myalgia, fatigue
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Serious adverse events are rare
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Contraindicated in individuals with severe allergic reactions to IXIARO components
View travel clinic’s pricing of the vaccine here
Frequently Asked Questions (FAQs)
What are the odds of getting Japanese encephalitis?
The risk for most travellers is extremely low: <1 case per 10,000,000 trips, or ~1 per 1,000,000 trips with underreporting considered. Risk increases with long-term rural travel, repeated visits, or travel during outbreaks.
Can encephalitis be cured?
Encephalitis is a medical emergency and requires urgent care. There is no antiviral treatment for JE. Management is supportive, focusing on stabilizing the patient and relieving symptoms such as fever, seizures, and brain swelling. Early care improves outcomes.
How is Japanese encephalitis transmitted?
JEV spreads through mosquito bites. Mosquitoes acquire the virus from pigs or birds. Humans do not transmit the virus to others. Rare transmission can occur via blood transfusion, organ transplantation, or mother-to-baby.
Can you fully recover from Japanese encephalitis?
Recovery depends on severity. Most infections are asymptomatic, but severe cases can cause permanent neurological, cognitive, or behavioural damage in 20–50% of survivors. Full recovery is possible for mild cases.
Why Choose Whole Health Pharmacy Travel Clinic in Edmonton?
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One-stop travel health service — assessment, prescriptions, and vaccines in a single visit
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No consultation, injection, or certificate fees
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Personalized travel health plans
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IXIARO® and other travel vaccines available
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Convenient Edmonton location